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WATER QUALITY
WATER PROTECTION BRANCH
MINISTRY OF WATER, LAND AND AIR PROTECTION
IDENTIFICATION KEYS
TO THE
AQUATIC PLANTS
OF
BRITISH COLUMBIA

TABLE OF CONTENTS

ABSTRACT

This document encompasses all the obligate aquatic plants known to occur in British Columbia and provides a number of identification keys to species, genera and families. Some species which are not yet known to be naturalized in BC are included if they are commonly used in garden pools or aquaria and may be found periodically even though they do not persist out of cultivation. For example {Myriophyllum aquaticum} and {Pontederia cordata} are established in several park ponds in the lower Fraser Valley, and a lake shore in Victoria, respectively. Species from neighboring areas which are gradually spreading or increasing their range are included in anticipation of them eventually becoming established in BC. As an example {Hydrilla verticillata} is found in lakes in Puget Sound, Washington State. Some other introduced species have recently become naturalized in BC, {Egeria densa} is widespread in a lake in Victoria and in northern Washington State, and more sites are likely to be found. These non-native and not-yet-naturalized species, which are not included in 'The Vascular Plants of British Columbia', are enclosed in {brackets} when mentioned in the text or keys.

Keys are based on both morphology and ecology. There is a list of printed reference materials which document some aspect of the aquatic species found in British Columbia and a glossary of technical terms used in the document. Several figures illustrate the different types of dissected underwater leaves, the parts of a flower and a plant and a glossary of leaf types. Illustrations of aquatic plants may be found in 'A Field Manual and Guide to the Collecting and Preserving of BC Aquatic Plants' and 'Aquatic Plants of British Columbia'. The distribution within BC and the habitats occupied by each species are reported. Common names are given for each.

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INTRODUCTION

What is an aquatic plant? The definition used in this document is: 'Aquatic plants are those whose photosynthetically active parts are submersed permanently or at least during the growing season'. This is a restrictive definition and means that most of the plants are obligate aquatics and not seasonal or marginal emergents. Most emergent and wetland plants only flower and fruit after water levels have subsided and many have only their roots submersed in water. The list of such species is quite extensive. The list of obligate aquatic plants, found only in deep permanent water of lakes and rivers is much shorter, about 100 species. Generally the species listed here reflects the authors experience in collecting plants in lakes, those species which were regularly found are included and a few commonly encountered marginal or non-obligate species are included. There is minimal overlap with the plants treated by MacKensie as Wetland Plants. With few exceptions Juncaceae, Cyperaceae and Gramineae are treated as wetland plants, not aquatics.

There will never be universal agreement as to where to draw the line between aquatic plants and wetland plants; these are arbitrary man-made boundaries in a natural continuum. We have attempted to have minimal overlap but make sure no species were omitted in assigning species to the Aquatic or Wetland category. Obligate aquatic plants usually grow in lakes and ponds or in permanent rivers, streams and sloughs. Some may survive for a while when water levels drop and their habitats are exposed but most grow in water deep enough that they are not normally exposed. Sub-tidal marine species are also included.

Rheophytes are excluded. They grow in habitats which are periodically inundated for short periods, often by flood waters, but they are established under non-flood conditions. They are firmly attached to rocks or trees to prevent being washed away by the swift currents. Rheophytes are more prevalent in tropical torrents. In high latitudes and altitudes many normally terrestrial plants may be found partially submersed in cold water much of the year.

Bryophytes are not treated except for the floating Riccia fluitans and Ricciocarpus natans. These two species may be conspicuous in some habitats and are distinct from the remaining submersed or marginal aquatic bryophytes. The treatment of Charophytes is relatively cursory. The major emphasis is on the flowering vascular plants or 'Aquatic Macrophytes'.

Not all of the plants listed are native or established outside of cultivation in British Columbia. Some species are aquarium plants that are introduced from time to time but do not persist, or are in cultivation but do not survive for long when they escape; others are major invasive weeds in other parts of the world which have not yet been found in BC but which may be expected eventually. People introduce many aquatic plants, both inadvertently and deliberately, some of which do eventually become established.

This manual includes one species of rush, Juncus supiniformis, three members of the Cyperaceae, Scirpus subterminalis, Scirpus lacustris and Dulichium arundinaceum but no grasses. Most members of the Cyperaceae, Juncaceae and Poaceae are marginal or wetland species which are difficult for non-specialists to identify at the species level. Some species may be found in the water, especially during high water, which are not included in these keys. The grass genus Glyceria is often found in shallow, marginal waters.

Field observations indicate that much of the variation in obligate aquatic plants which is often given specific recognition in herbaria may not be valid in nature. Many 'herbarium species' do not reflect reality. Aquatic plants are genetically plastic and respond to changing conditions with a tremendous amount of morphological variability. These morphological variants are responses to variable environmental conditions rather than indications of genetic distinctions at the species level. The species concept preferred by the author is a pragmatic 'lumping' approach. which may better reflect these field observations. However, in the interests of uniformity, the species concepts used in the four volume series 'The Vascular Plants of British Columbia' (ISSN 0843-6452) has been used in these keys. Occasional notes may be found to indicate the authors preference for another treatment.

The following pages include a list of all the species covered by these keys, a key to groups of aquatics based on their ecology, keys to each of the ecological groups, a general key to the aquatic plants of BC including a key to the aquatic plants with finely dissected submersed leaves, keys to the families and genera identified in the general key, a set of brief notes on the distribution, abundance and habitats of each species of aquatic plant, and references which may be useful in studying some aspects of the aquatic plants of BC.

Illustrations of the types of dissected underwater leaves which may be found are included. Synonyms are used very sparingly and only for species which have other long-established and well known names. They are given, after the distribution and habitat data, in [brackets]. More synonyms may be found in 'The Vascular Plants of British Columbia' which also contains extensive references to the BC flora.

A virtually complete list of common names gleaned from the world-wide literature is listed. There are many common names for widespread weedy species which grow in many different countries. Where more than one common name is given the preferred name for British Columbia is given first and the remainder follow in alphabetical order. Complex common names are often found in the literature and may be separate words, compound words or hyphenated words, they may also have capital or lowercase initial letters for each word. This can lead to a great many unique combinations. These combinations have been reduced to one multiple-word, non-hyphenated name with the first letter of the first word capitalized and all the rest of the words in lowercase.

The distribution limits of species are presented using vegetation zones as defined in 'The Vascular Plants of British Columbia'. The montane zone includes all continuous forests in BC except for the coastal lowlands and some islands included in the lowland zone. The subalpine zone is defined as that area above the montane zone and below the upper limit of conifers growing as an upright tree. This is represented by a meadow and tree-clump complex in the south and shrub Salix and scattered trees in the north. The alpine is above the subalpine where trees occur only as krummholz and vegetation is of tundra form. Steppe vegetation occurs in the interior and includes sagebrush or grasslands.

The various keys are not mutually exclusive and may be used together to help restrict the choices or confirm the identification of a species. Using the Ecological key may limit the number of species one has to choose from in the genus or species keys, or in the dissected leaf key. Similarly if the plant obviously has dissected underwater leaves then using the dissected leaf key is more efficient than using the general key. The Ecological key may result in only a few choices which can then be readily compared with the illustrations for identification.

Some of the keys are in hierarchical sets. The Ecological key restricts you to a group of plants and the subsequent species key identifies the individual species. The key to families restricts you to genera and species if you know the family, and the key to genera identifies species if you know the genus. If you already know the family or genus you can go directly to the key that is appropriate to the level of your knowledge of the plant in question, and not have to start each time with the general key to all the aquatic plants.

Using several different keys which should include the plant in question is a good check on your ability to use the keys and on the usefulness of the keys. You should get the same identification each time; if you do not perhaps you have made some assumptions about the plant which are not true or have taken the wrong fork in one of the keys. It is also possible that one of the keys can not handle some unanticipated variation in the specimen. All identifications made by keys should be checked with descriptions and illustrations, or better yet with herbarium specimens, to verify the identification. You may have a plant which is not included in the keys. The less experience you have with the species and the keys, the more important this verification becomes.

The general key to the aquatic plants of BC initially separates aquatic plants into 7 parts, for convenience and ease of use; this initial separation is based on ecology. Part 1 identifies herbaceous, fresh water plants which float freely on, or just under, the surface of the water. Part 2 identifies fully submersed, herbaceous, fresh water plants which are rooted or attached and have at least some finely dissected leaves. Part 3 identifies fully submersed, herbaceous, fresh water plants which are rooted or attached and do not have finely dissected leaves. Part 4 identifies herbaceous, fresh water plants which are rooted and emerge above the surface of the water but have cauline leaves that are opposite, whorled or clustered (more than one at each node). Part 5 identifies herbaceous fresh water plants which are rooted and emerge above the surface of the water but have cauline leaves that are alternate (only one at each node). Part 6 identifies herbaceous fresh water plants which are rooted and emerge above the surface of the water but have leaves in basal clusters as opposed to cauline leaves. Part 7 identifies fully submersed marine or brackish plants. With experience, or if you know which type of plant you have, you can go directly to the correct key. Marginal emergent shrubs such as Potentilla palustris are ommitted and dealt with as wetland species.

Ecological keys group plants without regard to the species and genus. They describe where and under what conditions the plants grow, in relation to the water level, and with regard to their morphology, which is often shaped by their habitat. Some are submersed, some float on the surface and some are emergent. A number of ecological classification systems have been proposed; all are useful for specific purposes and all have their limitations.

In Figure 1 some dissected leaves are shown since the pattern of dissection is diagnostic. Some of these patterns are quite distinctive and can be readily given a name: Myriophyllum species are all pinnate and Ceratophyllum species dichotomous, but most of the other types are more complex and not readily given a simple name.

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THE AQUATIC PLANTS OF BRITISH COLUMBIA

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GENERAL KEY TO THE AQUATIC PLANTS OF BRITISH COLUMBIA

Part 1: Floating Plants

A microscope is needed for positive identification of Azolla species.

Part 2: Plants With Finely Dissected Submersed Leaves

Part 3: Submersed Plants Without Finely Dissected Leaves

Section 1: Non-flowering Plants (Algae, Ferns and Quillworts- Isoetes)

A compound or dissecting microscope is required to positively identify species in Isoetes; magnification over 10x is needed to examine the megaspore surface.

Section 2: Flowering Plants (Angiosperms)

In Nuphar the large, showy, yellow, perianth members are sepals, the petals are smaller than the stamens and inconspicuous.

Mature fruits are generally needed for positive identification of Callitriche.

Part 4: Emergents- Opposite or Whorled Cauline Leaves

Our aquatic Equisetum all share the following characteristics: stems annual, usually with whorls of branches, distinct sterile and fertile stems, cones blunt.

Part 5: Emergents- Alternate Cauline Leaves

Part 6: Emergents- Basal or Terminal Leaf Clusters

In Sagittaria the usual non-achene key characters of bract length and shape and pedicel lengths have been found to be inconsistent and sufficiently variable even within one population as to be virtually useless as key characters. Many flowering, but not fruiting, collections are difficult to identify.

Part 7: Marine Plants

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CLASSIFICATION OF AQUATICS BY LIFE-FORM AND HABITAT

From an ecological point of view the growth-form of a plant and its usual habitat are often more important than the specific identification. Communities can often be distinguished by the growth-form of the plants present, which is constant world-wide, while the species may vary from place to place. Due to the morphological plasticity of aquatic plants no classification can be more than approximate and many exceptions will be found. A number of such classification schemes exist for various purposes. The following one may prove useful in reducing the number of choices when trying to identify an unknown plant, and in defining which group of plants normally inhabit certain zones. The key has been written to determine which group of plants is present, and under each group code mentioned in the key there is a list of species or genera which are applicable. Some plants will appear in more than one group. Generally only intact mature plants are keyed; fragments and seedlings would cause confusion.
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KEY TO MATURE AQUATIC PLANTS OF BRITISH COLUMBIA: based on Growth-Forms and Habitat

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THE SPECIES FOUND IN EACH GROWTH-FORM GROUP

Group Genera and Species Genera and Species
A {Eichhornia crassipes} {Limnobium laevigatum}
  {Limnobium spongia} {Pistia stratiotes}
  {Salvinia} {Trapa natans}
     
B Azolla caroliniana Azolla filiculoides
  Azolla mexicana Lemna minor
  Riccia fluitans Ricciocarpus natans
  Spirodela polyrhizas Wolffia borealis
  Wolffia columbiana {Wolffiella floridana}
     
C Ceratophyllum demersum Lemna trisulca
  Utricularia gibba Utricularia minor
  Utricularia vulgaris Wolffia borealis
  Wolffia columbiana {Wolffiella floridana}
     
D Lemna trisulca Utricularia gibba
  Utricularia minor Utricularia vulgaris
     
E Limosella aquatica Marsilea vestita
  Ranunculus flammula Ranunculus cymbalaria
     
F Sagittaria Vallisneria americana
  Sparganium resemble this group but are not scapose; they have leafy stems
     
G Isoetes Lilaeopsis occidentalis
  Lobelia dortmanna {Pilularia americana}
  Ranunculus flammula  
     
H {Cabomba caroliniana} Ceratophyllum
  Chara {Limnophila sessiliflora}
  Megalodonta beckii Myriophyllum
  Nitella Ranunculus aquatilis
  Ranunculus flabellaris Ranunculus sceleratus
  Tolypella intricata Utricularia intermedia
     
I Callitriche Chara
  Heteranthera dubia Hippuris vulgaris
  Juncus supiniformis Najas flexilis
  Nitella Phyllospadix (marine)
  Potamogeton berchtoldii Potamogeton filiformis
  Potamogeton foliosus Potamogeton friesii
  Potamogeton obtusifolius Potamogeton pectinatus
  Potamogeton pusillus Potamogeton robbinsii
  Potamogeton strictifolius Potamogeton vaginatus
  Potamogeton zosteriformis Ruppia maritima
  Subularia aquatica Tolypella intricata
  Zannichellia palustris Zostera (marine)
     
J Crassula aquatica Elatine rubella
  {Egeria densa} Elodea
  {Hydrilla verticillata} {Lagarosiphon major}
  Ludwigia palustris Potamogeton crispus
     
K Brasenia schreberi Caltha natans
  Nuphari Nymphaea
  Nymphoides Polygonum amphibium
  Potamogeton natans Ranunculus hyperboreus
  Ranunculus lobbii  
     
L Callitriche Potamogeton alpinus
  Potamogeton amplifolius Potamogeton epihydrus
  Potamogeton gramineus Potamogeton illinoensis
  Potamogeton natans Potamogeton nodosus
  Potamogeton oakesianus Potamogeton perfoliatus
  Potamogeton praelongus Potamogeton richardsonii
  Ranunculus aquatilis Ranunculus hyperboreus
  Ranunculus lobbii  
     
M Glyceria Sagittaria
  Scirpus subterminalis Sparganium
  Vallisneria americana  
     
N Callitriche Heteranthera dubia
  Juncus supiniformis Ludwigia palustris
  Mimulus Myosotis
  {Myriophyllum aquaticum} Nasturtium officinale
  Veronica  
     
O All the rooted, emergent plants belong to this group.
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KEYS TO THE SPECIES OF THE GROWTH-FORM GROUPS

Group A

Group B

A compound microscope is required to positively identify species of Azolla.

Group C

Group D

Group E

Group F

Juvenile or sterile specimens may be difficult to distinguish. (In Sagittaria the usual non-achene key characters of bract length and shape and pedicel lengths have been found to be inconsistent and sufficiently variable even within one population as to be virtually useless as key characters. Many flowering, but non-fruiting, collections are difficult to identify).

Group G

A compound or dissecting microscope is required to positively identify species of Isoetes. Magnification over 10x is needed to examine the megaspore surface.

Group H

Group I

Mature fruits are generally needed for positive identification of Callitriche.

Group J

Group K

Group L

Mature fruits are generally needed for positive identification of Callitriche.

Group M

Group N

Mature fruits are generally needed for positive identification of Callitriche.

Group O

These plants are keyed out in Parts 4, 5, and 6 of the General Key.
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KEYS TO AQUATIC GENERA AND SPECIES WITHIN FAMILIES

Key to the Alismataceae of British Columbiae

In Sagittaria the usual non-achene key characters of bract length and shape and pedicel lengths have been found to be inconsistent and sufficiently variable even within one population as to be virtually useless as key characters. Many flowering, but non-fruiting, collections are difficult to identify.

Key to the Aquatic Apiaceae of British Columbia

The lower-most leaves of many marginal Umbellifers may be under water, especially in the spring and may then be finely dissected with filiform segments. Sium sauve is especially prone to being found completely under water in the spring with all leaves filiform-dissected. Such plants will not key out properly in the general key. Cicuta is poisonous, use care when cutting open tubers to check for transverse septa. Wash your hands and your knife afterwards.

Key to the Aquatic Araceae of British Columbia

Key to the Cabombaceae of British Columbia

Key to the Characeae of British Columbia

Key to the Aquatic and Wetland Cyperaceae of British Columbia

Key to the Hydrocharitaceae of British Columbia

Key to the Lemnaceae of British Columbia

Key to the Menyanthaceae of British Columbia

Key to the Nymphaeaceae of British Columbia

Key to the Pontederiaceae of British Columbia

Key to the Aquatic Ranunculaceae of British Columbia

Key to the Aquatic Scrophulariaceae of British Columbia

Key to the Umbelliferae of British Columbia

See Key to the Apiaceae of British Columbia above

Key to the Zosteraceae of British Columbia

These are all marine plants.
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KEYS TO THE AQUATIC SPECIES WITHIN GENERA

Key to the Alisma of British Columbia

Key to the Azolla of British Columbia

A compound microscope is required to positively identify species in Azolla.

Key to the Callitriche of British Columbia

Mature fruits are generally needed for positive identification of Callitriche.

Key to the Aquatic Caltha of British Columbia

Key to the Ceratophyllum of British Columbia

Key to the Chara of British Columbia

Key to the Elodea of British Columbia

Key to the Aquatic Equisetum of British Columbia

This sub-set of all the Equisetum in BC share the following characteristics. Stems annual, usually with whorls of branches, cones blunt, fertile and sterile stems alike, ridges of the stem smooth or without tubercles or spicules, often cross-wrinkled, cones appear in summer.

Key to the Gratiola of British Columbia

Key to the Hydrocotyle of British Columbia

Key to the Isoetes of British Columbia

A compound or dissecting microscope is required to positively identify species in Isoetes. Magnification over 10x is needed to examine the megaspore surface.

Key to the Lemna of British Columbia

Key to the Limnobium of British Columbia

Key to the Aquatic Myosotis of British Columbia

Key to the Myriophyllum of British Columbia

Submersed leaves are simply pinnate. The key includes both native and two introduced species, one of which is widespread in aquaria and outdoor garden pools.

Key to the Nitella of British Columbia

Key to the Nuphar of British Columbia

In Nuphar the large, showy, yellow, perianth members are sepals; the petals are smaller than the stamens and inconspicuous.

Key to the Nymphaea of British Columbia

Key to the Nymphoides of British Columbia

Key to the Phyllospadix of British Columbia

Key to the Aquatic Polygonum of British Columbia

All our BC aquatic Polygonum share the following characteristics. Stipules red or brown, cylindrical or funnel-like, sometimes bristly, usually perennial and rhizomatous, fresh water.

Key to the Potamogeton of British Columbia

Key to the Aquatic Ranunculus of British Columbia

Key to the Sagittaria of British Columbia

In Sagittaria the usual non-achene key characters of bract length and shape and pedicel lengths have been found to be inconsistent and sufficiently variable even within one population as to be virtually useless as key characters. Many flowering, but non-fruiting, collections are difficult to identify.

Key to {Salvinia}

There is still considerable taxonomic confusion in Salvinia and since these plants are only expected as sporadic, non-persistent escapes from aquaria and garden ponds, there is little benefit in trying to identify individual species. The genus is readily recognizable but individual species are often only distinguished on technical and difficult characters. There is hybridization occurring and some 'species' are sterile hybrids and serious tropical weeds. The Salvinia auriculata complex includes, in part, such species as {Salvinia herzogii}, {Salvinia biloba}, and {Salvinia auriculata}

The other species include, in part, such species as {Salvinia natans}, {Salvinia sprucei}, {Salvinia cucullata}, {Salvinia rotundifolia}, {Salvinia minima} and {Salvinia oblongifolia}.

Key to the Sparganium of British Columbia

Key to the Utricularia of British Columbia

Key to the Aquatic Veronica of British Columbia

Key to the Wolffia of British Columbia

Key to the Zostera of British Columbia

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DISTRIBUTION, SELECTED COMMON NAMES AND HABITAT WITHIN BC

Not all of the plants in these keys are native or naturalized in British Columbia. Some are garden or aquarium plants that are introduced from time to time but do not persist, or are in cultivation but do not survive long when they escape. Others are major invasive weeds in other parts of the world and, although they have not yet been found in British Columbia, they are found in neighboring areas and are expected to be found in British Columbia eventually. People deliberately, and inadvertently, introduce many aquatic plants, some of which do eventually become permanently established. The following brief notes give an indication of the habitats of native and introduced aquatic and wetland plants in British Columbia and their general distribution range. A few selected common names are also given with the preferred British Columbia common name listed first and other common names following in alphabetical order. There are literally dozens of local common names, in many languages, for some of the more widespread species of aquatic weeds. A more complete list of these common names can be found in Aquatic Plants of British Columbia: Common Names, Selected References, Synonymy and Classification by Life-Forms and Habitat. Occasionally other pertinent or interesting notes are included.
Alisma
The species in this genus are commonly known as Mud plantains, Plantains and Water plantains
Alisma gramineum J. G. Gmel.
-Narrow leaved water plantain, Grass leaved water plantain
Shallow water of lakes, rivers, marshes and tidal flats in the lowland, steppe and montane zones; uncommon in southern BC; circumpolar.
Alisma plantago-aquatica L.
-American water plantain, Arrowhead, Broadleaf water plantain, Common water plantain, Heart shaped water plantain, Mud plantain
Shallow water of ponds, marshes and ditches in the lowland, steppe and montane zones; common in southern BC south of 52 degrees N; rare northward.
Azolla
-The species in this genus are commonly known as Fairy mosses, Mosquito ferns, Water velvets and Water ferns
Azolla caroliniana Willd.
-Carolina water fern
Surface of water in sloughs and ditches in the lowland zone; rare in south-western BC, primarily in the lower Fraser Valley. Introduced and available in garden shops, aquatic plant nurseries and the aquarium trade.
Azolla filiculoides Lam.
-Large mosquito fern, Duckweed fern, Pacific azolla
Surface of water in sloughs and ditches in the lowland zone; rare in south-western BC, primarily in the lower Fraser Valley. A European introduction with large populations where found. Commonly available in garden shops, aquatic plant nurseries and the aquarium trade.
Azolla mexicana K. B. Presl.
-Mexican mosquito fern
Surface of the water in sloughs and pools in the montane zone; rare in south-central BC, known from the Salmon Arm and Sicamous area.
Brasenia schreberi Gmel.
-Watershield, Dollar bonnet, Frog leaf, Junsai, Little water lily, Purple bonnet, Purple wendock, Schreber watershield, Water target
Ponds, lakes and slow-moving streams in the lowland, steppe and montane zones; common in south-western BC, less frequent in south-central BC.
{Cabomba caroliniana Gray}
-Fanwort, Carolina water shield, Fish grass, Parrot feather, Washington grass
A commonly introduced aquarium and garden pond plant, sometimes dumped but not known to overwinter outdoors in BC, established in Oregon and the lower Columbia River of Washington.
Calla palustris L.
-Wild calla, Bog arum, Calla lily, Water arum
Shallow water of swamps, marshes and lakes in the montane zone; frequent in BC north of 52 degrees N and east of the Coast Mountains, rare in south-central BC; circumpolar.
Callitriche
-The species of this genus are commonly known as Starworts, Water chickweeds and Water starworts.
Callitriche anceps Fern.
-Two edged water starwort
Shallow water of ponds and lakes in the lowland and montane zones; rare along the coast in BC.
Callitriche hermaphroditica L.
-Northern water starwort, Autumnal starwort
Shallow water of sow streams, ditches and sloughs in the lowland, steppe and montane zones; common in south-western BC, less frequent in south-central and south-eastern BC; circumboreal.
Callitriche heterophylla Pursh
-Diverse leaved water starwort, Large water starwort
Shallow water of slow streams, ditches, lakes and ponds in the lowland zone; frequent on southern Vancouver Island, rare in south-eastern BC.
Callitriche stagnalis Scop.
-Pond water starwort, Common starwort, Common water starwort
Shallow water of slow streams, ditches and ponds; infrequent in southern BC; introduced from Europe.
Callitriche verna L.
-Spring water starwort, Common water starwort, Vernal water starwort
Shallow water of slow streams, ditches and shorelines in the lowland, steppe and montane zones; frequent in southern BC; circumboreal.
Caltha natans Pallas
-Floating marsh marigold
Shallow water of ponds and lakes in the montane zone; locally frequent in north-eastern BC; amphiberingian.
Caltha palustris L.
-Yellow marsh marigold, Cowslip
Wet sites, bogs and shallow water in the lowland zone; rare along the coast.
Ceratophyllum
-The species in this genus are commonly known as Coontails, Foxtails, Hornworts and Water mosses.
Ceratophyllum demersum L.
-Common coontail, Common hornwort, Grey pimpled hornwort, Morass weed
Ponds, lakes and slow streams in the lowland, steppe and montane zones; common in southern BC, less frequent northwards.
Ceratophyllum echinatum Gray
-Spring hornwort, Prickly coontail, Spiny hornwort
Lakes and sloughs in the lowland and montane zones; locally frequent on southern Vancouver Island and the Gulf Islands, rare in the lower Fraser Valley and along the Alaska Highway.
Chara
-The species of this genus are commonly known as Chara, Musk grasses, Skunk grasses and Stoneworts.
Chara braunii Gm.
Little data is available on the abundance and distribution of charophytes in BC.
Chara canescens Desv. and Lois.
Little data is available on the abundance and distribution of charophytes in BC.
Chara globularis Thuill.
Little data is available on the abundance and distribution of charophytes in BC.
Chara vulgaris L.
Little data is available on the abundance and distribution of charophytes in BC.
Crassula aquatica (L.) Schoenl.
-Pygmyweed
Vernal pools and mud flats in the lowland zone; rare, scattered throughout southern BC; circumpolar. [Tillaea aquatica L.]
Dulichium arundinaceum (L.) Britt.
-Three way sedge, Dwarf bamboo, Pond sedge
Wet meadows, shallow water of lakes and stream sides in the lowland, steppe and montane zones; frequent in south-western BC, rare in south-central BC.
{Egeria densa Planch.}
-Brazilian waterweed, Anacharis, Argentine water weed, Brazilian elodea, Dense water weed, Giant elodea, Leafy elodea, Oxygen weed, South american elodea
Lakes, ponds and streams in the lowland zone; known from only a few sites in Victoria and Vancouver; introduced from South America. Naturalized and prolific where present and of concern as a weed displacing native species. Readily available in garden centers and aquarium shops. Well established in over a dozen lakes in Washington State.
{Eichhornia crassipes (Mart.) Solms}
-Water hyacinth, Florida devil
An often introduced garden pond species, but not yet known to overwinter outdoors in BC. Readily available in garden centers and aquarium shops. (None of the authors specimens, which grow and multiply prolifically in the greenhouse and outdoors in summer, has ever survived outdoors over the winter in Victoria).
Elatine rubella Rydb.
-Three flowered waterwort
Ditches, mud flats, shallow ponds and lake shores in the lowland zone; rare in south-western BC.
Elodea
-The species of this genus are commonly known as Ditch mosses, and Waterweeds.
Elodea canadensis Rich.
-Canadian waterweed, American elodea, Canadian pondweed, Common elodea, Water thyme
Lakes, ponds, streams and ditches in the lowland, steppe and montane zones; common in south-western BC, rare northward.
{Elodea longivaginata St. John}
-Long leaved waterweed
This species has not been confirmed in BC yet but is found east of the Rockies in Alberta, Montana and Wyoming. It is included in the keys in case a specimen is found in south-eastern BC or is introduced with garden plants. This species should be able to establish and overwinter successfully if introduced
Elodea nuttallii (Planch.) St. John
-Nuttall's waterweed, Slender waterweed, Western waterweed
Lakes, ponds and streams in the lowland, steppe and montane zones; rare in southern BC.
Equisetum
-The species of this genus are commonly called horsetails or scouring rushes.
Equisetum fluviatile L.
-Swamp horsetail, Water horsetail
Shallow water at lake margins in the lowland, steppe and montane zones; frequent throughout BC; circumpolar. This species often forms very extensive colonies with a distinctive horizontally-banded appearance en masse.
Equisetum palustre L.
-Marsh horsetail
Shallow water of marshes and swamps, stream banks and forests in the lowland, steppe and montane zones; frequent in southern BC, infrequent elsewhere; circumpolar. Commonly found marginally in subalpine lakes throughout BC.
Gratiola
-The species of this genus are commonly known as hedge hyssops.
Gratiola ebracteata Bentham
-Bractless hedge hyssop
Wet sites and shallow marginal water in the lowland zone; frequent in south-western BC.
Gratiola neglecta Torr.
-Common american hedge hyssop, Clammy hedge hyssop, Obscure hedge hyssop
Wet sites and shallow marginal water in the lowland, steppe and lower montane zones; rare in southern BC.
Heteranthera dubia (Jacq.) Macmill.
-Water star grass, Mud plantain, Water star weed
Ponds, lakes and slow-moving streams in the steppe and montane zones; infrequent in south-western and south-central BC.
Hippuris vulgaris L.
-Common mare's tail, Four leaved mare's tail, Water mare's tail
Shorelines, lakes, ponds and quiet open water in the lowland, steppe and montane zones; common throughout BC, less frequent along the coast; circumpolar.
{Hydrilla verticillata (L.) Royle}
-Hydrilla, Florida elodea, Oxygen grass, Oxygen weed, Water thyme
Lakes, ponds streams and other permanent water. This plant has not been found in BC yet, but it is established in Washington State. It is expected to overwinter successfully and become a weed once it is introduced.
Hydrocotyle ranunculoides L. f.
-Floating water pennywort
Ponds, shallow water of marshes and wet sites in the lowland zone; rare on south-eastern Vancouver Island.
Hydrocotyle verticillata Thunb.
-Whorled water pennywort
Streams, shallow water of marshes and wet sites in the lowland zone; rare, known from the lower Fraser valley.
Isoetes
-The species of this genus are commonly known as Quillworts, Bracksen grasses, Merllyn's grasses or Octopus plants.
Isoetes bolanderi Engelm.
-Bolander's quillwort
Shallow water of lakes and muddy sites in the subalpine zone; rare in south-eastern BC, known only from Akamina Pass.
Isoetes echinospora Dur.
-Bristle like quillwort
Lakes in the lowland to subalpine zones; infrequent throughout BC; circumpolar.
Isoetes howellii Engelm.
-Howell's quillwort
Shallow water of lakes (exposed in summer) in the steppe and montane zones; rare in south-central BC, known from Kamloops, Mara and Shuswap Lakes.
Isoetes maritima Underw.
-Coastal quillwort
Shallow water of lakes and other shallow water habitats in the lowland and montane zones; frequent in coastal BC, rare in south-central BC; amphiberingian.
Isoetes nuttallii A. Br.
-Nuttall's quillwort
Vernal pools and ephemeral winter seepages in the lowland zone; rare on south-eastern Vancouver Island.
Isoetes occidentalis Henderson
-Western quillwort
Lakes in the lowland, steppe and montane zones; frequent in southern BC.
Isoetes truncata (A. A. Eaton) Clute
-Slashed quillwort
Shallow water of lakes (exposed in summer) in the lowland zone; infrequent on south-eastern Vancouver Island (may be a hybrid between Isoetes echinospora and Isoetes maritima).
Juncus supiniformis Engelm.
-Spreading rush
Shallow water, wet muck, lake shores and open bogs in the lowland and montane zones; common in BC west of the Coast-Cascade Mountains.
{Lagarosiphon major Ridley}
-Lagarosiphon, African elodea, Oxygen weed
This 'weedy' species is distributed as an aquarium plant but it has not yet been found out of cultivation in BC.
Lemna
-The species of this genus are commonly known as Duckmeats, Duckweeds and water lentils.
Lemna minor L.
-Common duckweed, Lesser duckweed, Small duckweed, Water lentil
Ponds, lakes and slow moving streams in the lowland, steppe and montane zones; common throughout BC south of 55 degrees N, less frequent northward, absent in north-western BC and the Queen Charlotte Islands; circumpolar.
Lemna trisulca L.
-Star duckweed, Chain of stars, Forked duckweed, Ivy leaved duckweed
Ponds, lakes and slow moving streams in the lowland, steppe and montane zones; frequent throughout BC, absent in the Queen Charlotte Islands; circumpolar.
Lilaea scilloides (Poir.) Haum.
-Flowering quillwort
Mud flats, ponds, shallow water of lakes and wet sites in the lowland zone; rare in coastal BC, bipolar disjunct.
Lilaeopsis occidentalis Coult. and Rose
-Western lilaeopsis
Shallow water of marshes, lakes and tidal shores in the lowland zone; infrequent along the coast.
{Limnophila sessiliflora Blume}
-Limnophila
This species is distributed as an aquarium plant but it has not yet been reported out of cultivation in BC.
{Limnobium laevigatum} (Humb. and Bonpl.) Heine
-Amazonian frogbit
This species is distributed as an aquarium plant but it has not yet been reported out of cultivation in BC, [Limnobium stoloniferum].
{Limnobium spongia} (Bosc) Steud.
-American frogbit
This 'weedy' species is widely distributed as an aquarium plant but it has not yet been reported out of cultivation in BC.
Limosella aquatica L.
-Water mudwort, Limosella, Mudwort
Wet sites and shallow water in the lowland, steppe and montane zones; infrequent throughout BC south of 57 degrees N, absent from the Queen Charlotte Islands; circumpolar.
Lobelia dortmanna L.
-Water lobelia
Shallow water with a sandy, gravelly or otherwise firm bottom in lakes and ponds in the lowland zone; locally common in south-western BC.
Ludwigia palustris (L.) Ell.
-Water purslane, American seedbox, Creeping primrose, False loosestrife, Low seedbox, Marsh ludwigia, Marsh purslane, Marsh seedbox, Phthisis weed
Wet sites, shallow water of lakes and ponds in the lowland zone; rare on southern Vancouver Island and the lower Fraser Valley.
Lysimachia thyrsiflora L.
-Tufted loosestrife, Water loosestrife
Shallow water of marshes, lakes and ponds in the lowland and montane zones; frequent in BC.
Marsilea vestita Hook. and Grev.
-Hairy water clover, Clover fern, Hairy pepperwort, Water shamrock, Western water clover
Inundated lake margins (exposed in the summer) in the steppe and montane zones; rare in south-central BC, known from around Vernon.
Megalodonta beckii (Torr. ex Spreng.) Greene
-Water marigold, Bur marigold
Lake shores and shallow open water; rare known from south-eastern BC and Vancouver Island. [Bidens beckii (Torr. ex Spreng.)].
Menyanthes trifoliata L.
-Buckbean, Bog bean, Marsh trefoil
Bogs, shallow water of ponds and lakes and lake inlet and outlet fans in the lowland, montane and steppe zones; common throughout BC; circumpolar.
Montia fontana L.
-Water chickweed, Blinks
Wet meadows or shallow water in the lowland and montane zones; rare in north-western, south-western and south-central BC; circumpolar.
Myriophyllum The species of this genus are commonly known as Frills, Milfoils, Parrot feathers, Quills, and Water milfoils.
{Myriophyllum aquaticum (Vell. ) Verd.}
-Brazilian water milfoil, Golden myriophyllum, Parrot feather, Water feather
Shallow water of garden ponds and drainage ditches in the lowland zone; infrequent on southern Vancouver Island and the lower Fraser Valley; introduced from South America. Myriophyllum aquaticum is established in several lakes and rivers in Washington and Oregon, 2 lakes are in northwest Washington. [Myriophyllum brasiliense Cambess. in Hill et al.]
Myriophyllum farwellii Morong
-Farwell's water milfoil
Lakes and sloughs in the lowland and lower montane zones; infrequent, scattered throughout southern BC.
{Myriophyllum heterophyllum Michx.}
-Various leaved water milfoil, Broad leaf water milfoil, Foxtail, Mare's tail, Mermaid weed
Lakes and ponds in the lowland zone; rare, found in Beaver Lake in Stanley Park (now extirpated) and several ponds in Queen Elizabeth Park in Vancouver; introduced from eastern North America.
Myriophyllum hippuroides Nutt.
-Western water milfoil, Brown myriophyllum, Red water milfoil, Variable water milfoil
Lakes, ponds, sloughs and ditches in the lowland zone; infrequent, known from the lower Fraser Valley.
Myriophyllum pinnatum (Walt.) B. S. P.
-Green parrot's feather, Cut leaf water milfoil, Eastern water milfoil, Variable water milfoil
Lakes, ponds, sloughs and ditches in the lowland zone; infrequent, known from the lower Fraser Valley. [Myriophyllum scabratum Michx.]
Myriophyllum quitense H. B. K.
-Waterwort water milfoil, Andean water milfoil, Coarse water milfoil
Lakes and rivers in the lowland zone; rare on Vancouver Island.
Myriophyllum sibiricum Kom.
-Siberian water milfoil, American water milfoil, Northern water milfoil, Spiked water milfoil, Western spiked water milfoil
Lakes, ponds, rivers and other water bodies in the lowland and montane zones; frequent throughout BC; circumpolar. [Myriophyllum exalbescens Fern.]
Myriophyllum spicatum L.
-Eurasian water milfoil, Fox tail, Spiked water milfoil
Lakes, ponds, sloughs, irrigation ditches and other water bodies in the lowland, steppe and montane zones; infrequent, scattered throughout southern BC; introduced from Eurasia.
Myriophyllum ussuriense (Regel) Maxim.
-Ussurian water milfoil
Marginal habitats of lakes and rivers subject to seasonal water level fluctuations, and exposure in late summer, in the lowland and lower montane zones; rare and scattered on Vancouver Island, the lower Fraser Valley and south-central BC; amphiberingian.
Myriophyllum verticillatum L.
-Verticillate water milfoil, Green milfoil, Whorled water milfoil
Lakes and sloughs of the lowland to montane zones; frequent throughout BC; circumpolar.
Najas flexilis (Willd.) R. and S.
-Wavy water nymph, Common naiad, Northern naiad, Slender naiad, Slender water nymph
Ponds and marshes in the lowland, steppe and montane zones; common in southern BC; circumpolar.
Nasturtium officinale R. Br. in W. Ait.
-Common water cress, True water cress
Streams, ditches, swamp margins and shallow ponds in the lowland and montane zones; frequent in southern BC, rare northward; introduction from Europe. [Rorippa nasturtium-aquaticum (L.) Hayek]
Nitella
-The species of this genus are commonly known as Muskgrasses, Nitellas, Sandgrasses, Skunkgrasses, and Stoneworts.
Nitella acuminata A. Br.
Very little data is available on the abundance and distribution of charophytes in BC.
Nitella clavata Kutz.
Very little data is available on the abundance and distribution of charophytes in BC.
Nitella flexilis (L.) Ag.
Very little data is available on the abundance and distribution of charophytes in BC.
Nitella furcata (Roxb.) Ag.
Very little data is available on the abundance and distribution of charophytes in BC.
Nitella gracilis (Sm.) Ag.
Very little data is available on the abundance and distribution of charophytes in BC.
Nitella tenuissima (Desv.) Kutz.
Very little data is available on the abundance and distribution of charophytes in BC.
Nuphar
-The species of this genus are commonly known as Yellow lilies, Cow Lilies, Pond lilies, Water lilies, Spatterdocks and Water collards.
Nuphar polysepalum Engelm.
-Rocky mountain cow lily, Indian pond lily, Western pond or water lily
Lakes, ponds and slow-moving streams in the lowland, steppe and montane zones; common in BC south of 55 degrees N and west of 120 degrees W, less common northward and eastward.
Nuphar variegatum Engelm.
-Bullhead pond lily, Common yellow pond lily, Variegated pond lily
Lakes, ponds and slow-moving streams in the steppe and montane zones; frequent in eastern BC.
Nymphaea
-The species of this genus are commonly known as Fragrant water lilies, Pond lilies, Water nymphs, Water lilies and White water lilies
Nymphaea alba L.
-European white water lily
Ponds and lakes in the lowland and montane zones; rare on south-eastern Vancouver Island and at Clearwater; introduced from Europe.
Nymphaea leibergii Morong
-Pygmy water lily, Dwarf water lily, Little white water lily, Northern water lily, Small white water lily
Lakes, ponds and slow-moving streams in the montane zone; rare and scattered in eastern BC.
Nymphaea mexicana Zuccarini
-Yellow water lily, Banana water lily, Yellow lotus
Ponds and lakes in the lowland zone; rare on south-eastern Vancouver Island; introduced from Mexico.
Nymphaea odorata Ait.
-Fragrant water lily, Alligator bonnet, American water lily, Cow cabbage, Large white water lily, Sweet scented water lily, Toad lily, Water cabbage
Lakes, ponds and slow-moving streams in the lowland, steppe and lower montane zones; rare and scattered in south-western and south-central BC; introduced from Europe.
Nymphaea tetragona Georgi
-Pygmy water lily, Dwarf water lily, Little white water lily, Northern water lily, Small white water lily
Lakes, ponds and slow-moving streams in the lowland and montane zones; rare and scattered from the central coast and interior northward; circumpolar.
Nymphoides aquatica (Gmelin) O. Kuntze
-Banana plant, Fairy water lily
This species is found in garden ponds but has not yet been found naturalized.
{Nymphoides cordatum} (Ell.) Fernald
-Floating heart
This species is found in garden ponds but has not yet been found naturalized.
Nymphoides peltata (Gmelin) O. Kuntze
-Water fringe, Floating heart
This species is found in garden ponds but has not yet been found naturalized in BC, it is established in Washington State near Spokane.
Phyllospadix
-The species of this genus are commonly known as Sea grasses or Surf grasses.
Phyllospadix scouleri Hooker
-Scouler's surf grass
Exposed, rocky, intertidal to subtidal shores in the lowland zone; common along the coast.
Phyllospadix serrulatus Rupr. ex Aschers.
-Toothed surf grass
Sheltered intertidal and subtidal shores in the lowland zone; frequent along the coast.
Phyllospadix torreyi S. Wats.
-Torrey's surf grass
Exposed, rocky, intertidal to subtidal shores in the lowland zone; infrequent in coastal BC.
{Pilularia americana R. Br.}
-American pillwort
Shallow water of ponds in the lowland zone; rare in south-western BC; introduced from south-western North America, known from a pond in the UBC botanical gardens.
{Pistia stratiotes L.}
-Water lettuce, Shell flower, Water cabbage, Water bonnet
This is a free-floating tropical species introduced in the aquarium and garden pool trade but it has not yet been found out of cultivation It is not expected to overwinter outdoors in BC. (None of the authors specimens have ever overwintered successfully. There is a long list of endemic common names, mostly in southeast Asian languages and tropical American tongues).
Polygonum
-The species in this genus are commonly known as Door weeds, Knot weeds, Smart weeds and Tear thumbs.
Polygonum amphibium L.
-Water smartweed, Amphibious bistort, Water smartweed, Floating knotweed, Marsh smart weed, Swamp persicaria, Swamp smart weed, Water heartsease, Water knot weed, Water persicaria
Shorelines, ditches and shallow water of lakes and ponds in the lowland, steppe and montane zones; common throughout BC except for the Queen Charlotte Islands and adjacent coast.
Polygonum hyropiper L.
-Marshpepper smartweed, Annual smartweed, Common smartweed, Water smartweed, Marsh pepper, Water pepper
Moist ditches, shallow marginal sites and disturbed places in the lowland, steppe and montane zones; infrequent in south-western and south-central BC; introduced from Eurasia.
Polygonum hydropiperoides Michx.
-Swamp smartweed, Marshpepper smartweed, Mild water pepper, Wild water pepper
Wet swampy sites, shorelines and shallow marginal water of lakes and rivers in the lowland, steppe and montane zones; rare in southern BC.
Polygonum lapathifolium L.
-Willow weed, Nodding smartweed. Pale smartweed
Wet swampy sites, wet meadows, shorelines and shallow marginal water of lakes and rivers in the lowland, steppe and montane zones; common in south-western BC, rare elsewhere in southern and north-eastern BC.
{Pontederia cordata Lour.}
-Pickerel weed, Pikeweed, Wampee
This introduced subtropical species is often found in garden pools and is known from Glen Lake in Victoria where it has overwintered successfully for over a decade, but not spread from its original site. (The author has kept a population growing, outdoors, in a tub of water for many years; it suffered severely during the cold winter of 1995 but survived and recovered completely).
Potamogeton The species of this genus are commonly known as Fishweeds, Pondweeds and River weeds.
Potamogeton alpinus Balbis
-Northern pondweed, Alpine pondweed, Red pondweed
Nutrient poor lakes and sloughs in the lowland, steppe and montane zones; frequent throughout BC; circumpolar.
Potamogeton amplifolius Tucker.
-Large leaved pondweed, Bass weed, Big pondweed, Broad pondweed, Large leaf pondweed, Muskie weed
Lakes and ponds in the lowland and montane zones; frequent in south-western BC, infrequent east of the Coast-Cascade Mountains south of 55 degrees N.
Potamogeton berchtoldii Fieb. in Bercht.
-Berchtold's pondweed, Small pondweed
Lakes, ponds, sloughs and ditches in the lowland, steppe and montane zones; common throughout BC; circumpolar.
Potamogeton crispus L.
-Curled pondweed, Crimped pondweed, Crisp pondweed, Curled pondweed, Curly leaf pondweed, Curly cabbage or muckweed
Nutrient rich lakes, ponds and sloughs in the lowland and steppe zones; common in BC south of 50 degrees N; introduced from Eurasia.
Potamogeton epihydrus Raf.
-Ribbon leaved pondweed, Leafy pondweed, Nuttall's pondweed
Peaty lakes, ditches and ponds from the lowland and steppe to subalpine zones; common in coastal BC, infrequent east of the Coast-Cascade Mountains.
Potamogeton filiformis Pers.
-Slender leaved pondweed
Calcium rich lakes in the lowland, steppe and montane zones; frequent east of the Coast-Cascade Mountains, rare along the coast; circumpolar.
Potamogeton foliosus Raf.
-Closed leaved pondweed, Leafy pondweed, Narrow leaf pondweed
Lakes, ponds and ditches in the lowland, steppe and montane zones; frequent in BC south of 55 degrees N, rare in northern BC.
Potamogeton friesii Rupr.
-Flat stalked pondweed, Fries' pondweed
Lakes, ponds and ditches in the lowland, steppe and montane zones; frequent in BC east of the Coast-Cascade Mountains, infrequent in coastal BC; circumpolar.
Potamogeton gramineus L.
-Grass leaved pondweed, Variable leaf pondweed
Lakes, lake margins, ponds in peat bogs, ditches and slow flowing streams and rivers in all but the alpine zone; frequent throughout BC; circumpolar. A very plastic and variable species often found growing as a rosette on damp mud when water levels recede.
Potamogeton illinoensis Morong
-Illinois pondweed
Lakes and slowly flowing streams in the steppe zone; infrequent in southern BC east of the Coast-Cascade Mountains.
Potamogeton natans L.
-Floating leaved pondweed, Bass weed, Broad leaf pondweed, Common floating pondweed, Floating brown leaf, Muskie weed
Lakes, streams and ponds from the lowland and steppe to subalpine zones; common throughout BC; cosmopolitan.
Potamogeton nodosus Poir.
-Long leaved pondweed, American pondweed, Knotty pondweed, Loddon pondweed, River pondweed, River weed
Lakes and sloughs of the lowland zone; infrequent in the lower Fraser Valley, rare elsewhere; cosmopolitan.
Potamogeton oakesianus Robbins
-Oakes' pondweed
Lakes in the lowland and steppe zones; rare in southern BC, found in Steelhead and Mara Lakes.
Potamogeton obtusifolius Mertens and Koch
-Blunt leaved pondweed, Grassy pondweed
Lakes and sloughs in the lowland, steppe and montane zones; infrequent throughout BC; circumpolar.
Potamogeton pectinatus L.
-Sago pondweed, Big pondweed, Large sheath pondweed, Bushy pondweed, Fennel leaved pondweed, Fine leaf pondweed, Giant pondweed, Narrow leaf pondweed, Sheathed pondweed, Slender pondweed, Thread leaf pondweed
Lakes, ponds and estuaries in the lowland, steppe and montane zones; frequent in BC east of the Coast-Cascade Mountains, infrequent on the coast; cosmopolitan.
Potamogeton perfoliatus L.
-Perfoliate pondweed, Bass weed, Clasping leaf pondweed, Muskie weed, Perfoliate pondweed, Redhead grass
Lakes in the montane zone; rare in northern BC, found in Swan Lake in the Cassiar Range; circumpolar.
Potamogeton praelongus Wulf.
-Long stalked pondweed, Muskie weed, White stem pond weed
Lakes in the lowland, steppe and montane zones; frequent throughout BC; circumpolar.
Potamogeton pusillus L.
-Small pondweed, Baby pondweed, Narrow leaf pondweed, Slender leaf pondweed, Small pondweed
Lakes, ponds, sloughs and ditches in the lowland, steppe and montane zones; frequent in BC; circumpolar.
Potamogeton richardsonii (A. Benn.) Rydb.
-Richardson's pondweed, Clasping leaf pondweed
Lakes, ponds and sloughs in the lowland, steppe and montane zones; common throughout BC; amphiberingian.
Potamogeton robbinsii Oakes
-Robbin's pondweed, Fern pondweed, Robbin's pondweed
Lakes in the lowland, steppe and montane zones; frequent in coastal BC, infrequent east of the Coast-Cascade Mountains.
Potamogeton strictifolius Bennett
-Stiff leaved pondweed, Narrow leaf pondweed
Lakes in the lowland and steppe zones; rare in south-central and south-eastern BC, found in Kawkawa, Mara and Windermere Lakes.
Potamogeton vaginatus Turcz.
-Sheathing pondweed
Lakes in the montane zone; infrequent east of the Coast-Cascade Mountains; circumpolar.
Potamogeton zosteriformis Fern.
-Eel grass pondweed, Flatstem pond weed
Lakes in the lowland, steppe and montane zones; frequent in BC east of the Coast-Cascade Mountains, infrequent in coastal BC.
Ranunculus
-The species in this genus are commonly known as Buttercups and Crowfoots.
Ranunculus aquatilis L.
-White water buttercup, Water crowfoot, Aquatic buttercup
Lakes, ponds and slow-moving streams in the lowland, steppe, montane and subalpine zones; frequent throughout BC.
Ranunculus circinatus Sibth.
-Stiff leaved water buttercup
Ponds and slow-moving streams in the lowland, steppe and montane zones; common in southern BC east of the Coast-Cascade Mountains, less frequent northward. [Ranunculus subrigidus]
Ranunculus cymbalaria Pursh
-Shore buttercup, Desert buttercup, Seashore buttercup
Moist saline or alkaline shorelines, marshes, wet meadows and shallow marginal water of lakes and ponds in the lowland, steppe and montane zones; common in southern BC, less frequent northward; circumpolar.
Ranunculus flabellaris Raf.
-Yellow water buttercup, Yellow crowfoot, Pursh's buttercup
Ponds and shallow marginal water of lakes and ponds in the steppe and montane zones; rare and scattered in BC east of the Coast-Cascade Mountains.
Ranunculus flammula L.
-Lesser spearwort, Creeping buttercup, Creeping spearwort
Wet seepage sites along the shores of lakes, wet meadows and shallow marginal water of lakes and streams in the lowland, steppe and montane zones; common throughout BC; circumpolar.
Ranunculus gmelinii DC.
-Small yellow water buttercup
Ponds, shallow streams and wet sites in the lowland, steppe and montane zones; common throughout BC except rare along the coast; amphiberingian.
Ranunculus hyperboreus Rottb.
-Arctic buttercup, Far northern buttercup, Floating buttercup
Ponds and shorelines in the montane zone; frequent in northern BC, rare southward to 53 degrees N; circumpolar.
Ranunculus lobbii (Hiern) A. Gray
-Lobb's water buttercup
Vernal pools and wet sites in the lowland zone; rare on south-eastern Vancouver Island, not collected for 50 years.
Ranunculus sceleratus L.
-Cursed buttercup, Cursed crowfoot, Celery leaved buttercup, Celery leaved crowfoot
Ponds and wet sites in the lowland, steppe and montane zones; common in southern BC east of the Coast-Cascade Mountains, infrequent elsewhere.
Riccia fluitans L.
-Crystalwort, Dissected liverwort, Floating liverwort, Floating crystalwort
This native aquatic liverwort is rarely collected or reported in aquatic habitats, but is known from a number of scattered sites in BC.
Ricciocarpus natans (L.) Corda
-Purple fringed riccia, Ricciocarpus
This native liverwort is rarely collected or reported in aquatic habitats, but is known from a number of scattered sites in BC. (The world distribution is cosmopolitan; the author has seen it growing with Victoria amazonica in the Peruvian Amazon basin and noted it in many eutrophic sites throughout BC).
Ruppia maritima L.
-Ditch grass, Sea tassel, Widgeon grass
Tidal marshes, ponds, lakes and ditches in the lowland, steppe and montane zones; common along the coast and in south-central BC, rare in south-eastern BC; circumpolar. A very variable species or species-complex
Sagittaria
-The species in this genus are commonly known as Arrow heads, Duck potatoes, Swamp potatoes and Wapato.
Sagittaria cuneata Sheldon
-Arum leaved arrowhead, Northern arrowhead, Western wapato
Wet ditches, ponds and lakes in the lowland, steppe and montane zones; common in BC south of 55 degrees N and east of the Coast-Cascade Mountains, less frequent westward and northward.
Sagittaria latifolia Willd.
-Common arrowhead, Broadleaf, Coastal and Slender arrowhead
Wet ditches, ponds, lake shores and marshes in the lowland, steppe and montane zones; uncommon in BC south of 56 degrees N, absent from the Queen Charlotte Islands, Northern Vancouver Island and the adjacent coast.
Salvinia
-The species in this genus are commonly known as Floating ferns, Floating mosses, Salvinia, Water ferns and Water spangles. Most specific common names are in southeast Asian dialects where the plants are rampant.
Introduced tropical free-floating ferns present in the aquarium and water garden trade, occasionally dumped in local lakes but not yet known, or expected, to overwinter in BC. (Although specimens the author has grown in outdoor pools have never overwintered successfully, spores are produced and should be able to survive the winter in suitable habitats. One species, {Salvinia natans}, is known from Europe and is capable of growth in temperate conditions, these plants could become naturalized in BC. {Salvinia auriculata} [Salvinia molesta] is a tropical species complex, none of which are likely to become established).
Scheuchzeria palustris L.
-Scheuchzeria
Shallow marginal water of lakes and ponds and bogs in the lowland and montane zones; frequent in south-western, central and eastern BC, also along the coast.
Scirpus lacustris L.
-American bulrush, Big bulrush, Giant bulrush, Greater bulrush, Porcupine quill bulrush, Slender bulrush, Softstem bulrush, True bulrush, Zebra rush, Zebra bulrush, Tule
Shallow water of marshes, lakes and streams in the lowland, steppe and montane zones; common throughout BC. (A common species-complex throughout BC which includes Scirpus validus Vahl and Scirpus acutus Muhl. in Bigel.).
Scirpus subterminalis Torr.
-Water clubrush, Aquatic sedge, Swaying rush
Shallow ponds and streams in the lowland zone; infrequent in coastal and south-central BC
Sparganium The species in this genus are commonly known as Bur reeds.
Sparganium angustifolium Mich.
-Narrow leaved bur reed, Floating leaf bur reed, Green fruited bur reed, Slender bur reed, Unbranched bur reed, Western bur reed
Ponds, ditches and lake shores in all but the alpine zone; common throughout BC; circumpolar. A highly variable species or species-complex which sometimes includes Sparganium emersum as well.
Sparganium emersum Rehm.
-Emersed bur reed
Streams, ditches, ponds and lake shores in the lowland, steppe and montane zones; common in coastal BC, less frequent elsewhere; circumpolar.
Sparganium eurycarpum Engelm. in A. Gray
-Broad fruited bur reed, Big, Common bur reed, Eastern bur reed, Giant bur reed, Large bur reed, Three square bur reed
Wet meadows, shallow ponds and lake shores in the lowland, steppe and montane zones; infrequent in southern and eastern BC.
Sparganium fluctuans (Morong) B. L. Robins.
-Water bur reed, Broad ribbon leaf, Floating leaf bur reed, Shining bur reed
Ponds, lake shores and slow-moving streams in the lowland and montane zones; rare in south-western and central BC; circumpolar.
Sparganium glomeratum Laest. ex Beurl.
-Glomerate bur reed
Ponds and lake shores in the lowland and montane zones; rare in west-central BC, known only from Buck Channel, Queen Charlotte Islands and the Smithers area.
Sparganium hyperboreum Laest. ex Beurl.
-Northern bur reed
Ponds and lake shores in the lowland and montane zones; infrequent throughout BC; circumpolar.
Sparganium natans L.
-Small bur reed
Ponds, lake shores and slow-moving streams in the lowland and montane zones; common throughout all but north-western BC; circumpolar. [Sparganium minimum].
Spirodela polyrhiza (L.) Schleid.
-Great duckweed, Big, Greater duckweed, Larger duckweed
Ponds, lakes and slow-moving streams in the lowland, steppe and montane zones; common in south-western and south-central BC, infrequent elsewhere, absent on northern Vancouver Island, the Queen Charlotte Islands and north-western BC; circumpolar.
Subularia aquatica L.
-Water Awlwort
Streams, shorelines, tidally inundated shores, shallow ponds and lakes; infrequent in southern BC.
Tolypella intricata (Trent.) Leonh.
Very little data is available on the abundance and distribution of charophytes in BC.
{Trapa natans L.}
-Water chestnut, Caltrops, Water nut
This species has not yet been found in BC but if introduced it should be able to overwinter and could become a pest.
Utricularia
-The species in this genus are commonly known as Bladderworts.
Utricularia gibba L.
-Humped bladderwort, Cone spur bladderwort, Eastern bladderwort, Small bladderwort, Yellow bladderwort
Lake bottoms and margins, muddy disturbed sites in the lowland zone; rare on southern Vancouver Island and in the Vancouver area.
Utricularia intermedia Hayne
-Flat leaved bladderwort, Mountain bladderwort
Oligotrophic and dystrophic lakes and marshes in the lowland, steppe and montane zones; frequent south of 55 degrees N, rare northward; circumpolar.
Utricularia minor L.
-Lesser bladderwort, Northern bladderwort, Small bladderwort
Oligotrophic and dystrophic lakes and peat bog pools in the lowland and montane zones; common on Vancouver Island and the Queen Charlotte Islands, less frequent inland; circumpolar.
Utricularia vulgaris L.
-Greater bladderwort, Common bladderwort
Lakes and ponds in the lowland, steppe and montane zones; common south of 55 degrees N in BC, less frequent northwards; circumpolar.
Vallisneria The species in this genus are commonly known as Eel grasses, Ribbon grasses, Tape grasses and Water celery's.
Vallisneria americana Michx.
-American tapegrass
Lakes, ponds and streams in the lowland and montane zones; rare in south-western and south-central BC; introduced from eastern North America.
Veronica
-The species in this genus are commonly known as Brooklimes and Speedwells.
Veronica anagallis-aquatica L.
-Blue water speedwell, Brook pimpernel
Wet ditches and, shallow marginal water of streams and lakes in the lowland zone; rare in southern and central BC; introduced from Europe.
Veronica beccabunga L.
-American brooklime, American speedwell
Wet ditches, stream and lake edges and shallow marginal water in the lowland, steppe and montane zones; common in southern BC, infrequent northward. [Veronica americana Schwein.]
Veronica catenata Pennel
-Pink water speedwell, Tufted water speedwell
Wet ditches, slow streams, stream and lake edges and shallow marginal water in the lowland and montane zones; rare in southern BC; circumpolar.
Veronica scutellata L.
-Marsh speedwell
Swamps, stream and lake edges and shallow marginal water in the lowland, steppe and montane zones; frequent throughout BC.
Wolffia
-The species in this genus are commonly known as Water meals.
Wolffia borealis (Engelm. ex Hegelmaier) Landolt and Wildi
-Northern water meal, Dotted water meal, Papillary water meal, Spotted water meal, Southern water meal
Ponds, lakes and slow-moving streams in the lowland and montane zones; rare in the lower Fraser Valley and south-eastern BC (Creston). This species is probably more common than its collection reports indicate.
Wolffia columbiana Karsten
-Columbian water meal
Ponds and lakes in the lowland zone; rare in south-western BC, known only from Beaver, Blenkinsop and Swan Lakes. This species is probably more common than its collection reports indicate.
{Wolffiella floridana (J. D. Smith) Thompson}
-Florida water meal
This species has been tentatively identified by the author from a lake near Smithers but no specimens exist for confirmation.
Zannichellia palustris L.
-Horned pondweed, Common poolmat, Grass wrack
Shallow, often calcareous or brackish lake shores, slow-moving streams and tidal marshes in the lowland, montane and steppe zones; frequent in mainland BC south of 54 degrees N, less frequent northward and on Vancouver Island; cosmopolitan.
Zostera
-The species in this genus are commonly known as Eel grasses.
Zostera japonica Ascher and Grabn.
-Japanese eelgrass
Tidal mud-flats along the coast in the lowland zone; rare in south-western BC, known only from Boundary Bay and Tsawwassen; introduced from Asia.
Zostera marina L.
-Common eelgrass, Wrack
Sheltered coastal waters in the lowland zone; common in coastal BC; cosmopolitan.
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EXCLUDED SPECIES OF AQUATIC PLANTS

Elatine triandra Schkuhr.
This species was cited by Scoggan in 1978 but our material is actually Elatine rubella (Mason-1956).
Hydrocotyle umbellata L.
This species was reported by Taylor and MacBryde in 1977 but no BC material has been seen.
Lemna gibba L.
This species was reported by Taylor and MacBryde in 1977 but no BC material has been seen. Reports are likely mis-identified, abnormal specimens of Lemna minor.
Limosella subulata Ives.
Reports of this species by Taylor in 1974 and Taylor and McBride in 1977 are based on mis-identifications of Limosella aquatica.
Potamogeton diversifolius Raf.
This species was reported by Hitchcock et al. in 1969 and Brayshaw in 1985 but no specimens have been seen. No BC specimens were cited by Reznicek and Bobbette in 1976.
Potamogeton fibrillosus Fern.
The specimen collected in Manning Park on which the report of this species was based is in poor shape, with immature fruits, and difficult to identify. Haynes and Reveal in 1973 and Haynes in 1974 treated this as Potamogeton foliosus var. fibrillosus (Fernald) Haynes and Reveal.
Sparganium americanum Nutt.
This is treated as a BC species by Fernald in 1950, Boivin in 1966/67, Taylor and McBride in 1977 and Brayshaw in 1985. However, no material has been found and it is likely that the material referred to by these authors is actually a part of the Sparganium angustifolium complex.
Utricularia occidentalis A. Gray (U. ochroleuca R. Hartm.)
The report of this species by Macoun in 1913 and Henry in 1915 was based on a specimen of Utricularia minor (Ceska and Bell-1973).
Vallisneria spiralis L.
This species was cited by Taylor and MacBryde in 1977 but is apparently absent from BC, Brayshaw in 1985, and from Canada, Scoggan in 1978. Our material is referred to Vallisneria americana. Vallisneria spiralis is a European species which is presumed distinct from Vallisneria americana.
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REFERENCES TO THE AQUATIC PLANTS OF BRITISH COLUMBIA

These include Manuals, Texts, Floras, Papers, Keys, Books and other reference sources which contain information about the biology, common names, distribution, culture, identification and taxonomy of the aquatic plants found in British Columbia. Species which are not yet known to be naturalized in BC are also referenced if they are commonly used in garden pools or aquaria and may be found from time to time. Species from neighboring areas which are gradually spreading or increasing their range are also included in anticipation of them reaching BC soon. This is only a partial list of useful references. See also the references in The Vascular Plants of British Columbia, ISSN 0843-6452.
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GLOSSARY

Abaxial
on the side of a structure turned away from the main axis.
Achene
a dry, single-seeded fruit that does not open at maturity.
Acuminate
tapering to a narrow tip or concave point, the sides generally concavely narrowing.
Acute
gradually tapering to a point, the side straight and not convex.
Aerenchyma
cortical tissue containing air spaces in the parenchyma.
Algae
non-flowering thalloid plants which reproduce by unicellular structures or by multicellular structures in which each cell forms a gamete, there are no sterile cells.
Alpine
this is the highest vegetation zone where trees occur only as Krummholz and other vegetation is short and known as tundra.
Alternate
any arrangement of leaves or other parts which is not opposite or whorled, only one at each node or given location on the stem.
Amphiberingian
occurring on both side of the Bering Strait as a result of past migration across the Bering land bridge. Potamogeton pectinatus is an example and many of our Cyperaceae belong to this group of plants.
Annual
the vegetative body of the plant dies at the end of each growing season and the plant regrows from seeds or turions and similar structures each year.
Anther
the pollen producing sac of a stamen.
Anthesis
the period of time when a flower is fully open.
Apex
the tip, point or end of the leaf furthest away from the connection to the petiole or stem. The uppermost part of a plant.
Apical
the one nearest the apex or located at the apex.
Apices
plural of apex.
Apiculate
having a small sharp projection on the end.
Appressed
lying close and flat, pressed against for the entire length.
Aquatic
living in or on the water. The photosynthetically active portions of the plants are permanently, or at least for several months of the year, submersed in water or float on the surface of the water.
Aril
a fleshy outgrowth on the outer covering of a seed.
Arillate
having arils.
Aromatic
having an odour or smell.
Articulated
jointed, separating at a joint by a clean scar at maturity.
Attenuate
gradually tapering to a slender base or apex.
Auricles
ear shaped lobes or appendages.
Auriculate
having auricles, describes leaf bases which have an auricle on either side of the petiole.
Axes
plural of axis.
Axial
related to an axis.
Axil
the space or area between the junction of a leaf or its petiole and the stem.
Axile
central or on the axis, in placentation the ovules are attached to the common axis in the center.
Axillary
attached in the axils.
Axis
a line running lengthwise through an organ or a plant, the stem is usually the axis.
Basal
at or forming the base or bottom part.
Base
the bottom most part, the portion of a rooted stem at ground level, the junction area between roots and stems.
Beak
a long slender projection from a wider structure.
Berry
a fleshy fruit with no stone and usually with many small seeds in the pulp.
Bi
a prefix meaning twice or again, bi-pinnate means the leaves are pinnate and the pinnae are also pinnate.
Bidentate
with 2 teeth or doubly toothed.
Bifacial
with an obvious and distinguishable top and bottom surface.
Bifid
two parted, two lobed, forked or divided.
Bilabiate
with two lips.
Bipolar disjuncts
these plants occur in both southern and northern polar or temperate zones but not in the mid latitudes in-between. Lilaea scilloides is an example.
Biseriate
in two rows or series.
Blade
the lamina or flat expanded portion of a leaf.
Bladder
a small sac or bag.
Bloom
a whitish or bluish waxy powder that readily rubs off; a flower.
Blue-green algae
a specific taxonomic group of algae, evolutionarily primitive, often producing toxins and blooms.
Blunt
not sharp or acute., abrupt.
Bog
a wet poorly drained depression filled with peat or sphagnum moss, acidic and nutrient poor, vegetation cover of mosses and shrubs.
Brackish
partially salt and partially fresh water, in estuarine and interior high evaporation areas.
Bract
a small leaf or scale often associated with an inflorescence.
Bracteate
having bracts.
Bracteoles
small bracts.
Branchlets
small branches or subdivisions of branches.
Bristle
a rigid or stiff hair
Bryophyte
mosses and liverworts.
Calyx
collectively the sepals of the flower as opposed to the corolla which is composed of the petals.
Capillary
hair-like.
Capitate
head-shaped, globose.
Capsule
dry dehiscent fruits with seeds inside.
Carpel
the ovary, style and stigma, contains the ovules and later the seeds.
Cauline
on or belonging to the stem, especially the upper portion.
Chaff
membranous scales or bracts on the receptacle of the Asteraceae, floral parts of grasses, glumes of grasses.
Circinate
coiled from the top down like fern fronds, rolled or coiled so that the apex is in the center.
Circumpolar
distributed all around the (north) pole; can be subdivided into circumboreal or circumarctic. Calla palustris is an example and many of our Cyperaceae belong to this group of plants.
Clasping
wrapped around or enveloping.
Clavate
club shaped, thicker at the apical end.
Cluster
an inflorescence of small, closely crowded flowers.
Coarse
not fine or delicate, big and crude.
Colony
small group all living or aggregated together.
Compound
formed of several similar parts, a leaf formed of several separate leaflets
Concave
bulged inwards towards the axis.
Congested
crowded together.
Connate
united with the other similar parts into one organ as growth proceeds.
Connective
the part of the filament which connects the anthers or anther lobes.
Contiguous
abutting directly without any gap between them.
Convex
bulged outwards away from the axis.
Convolute
coiled, folded or rolled so that one part is covered by another.
Cordate
heart shaped.
Corm
solid fleshy underground base of a stem, often a storage organ but of different origin and structure than a bulb.
Corolla
the petals of a flower, as opposed to the calyx which is composed of the sepals.
Corolla limb
the apical expanded or unfused portion of a basally fused corolla.
Corolla tube
the portion of the corolla where the petals are fused together and form a tubular structure rather than separate petals.
Corona
a crown of cells on the oogonium of Chara, a structure developing between the corolla and stamens.
Coronula
a small corona in Chara.
Cortex
parenchyma tissue between the epidermis and endodermis, the outer cellular layer of Chara.
Cortical
referring to the cortex in Chara.
Corticate
having a cortical layer in Chara.
Cosmopolitan
distributed all over the world. These are usually 'weedy' species which are cultivated and have been introduced but some native plants have this type of distribution naturally. Ricciocarpus natans is an example.
Crenate
leaf margins with broad rounded teeth and narrow gaps.
Crenulate
small crenate teeth.
Crispate
wavy or curled along the edge.
Cucullate
hooded with the edges curved inwards or rolled up like the point of a slipper.
Culm
the jointed stem of herbaceous grasses which is hollow except at the swollen nodes, also sedge stems.
Cuneate
wedge shaped.
Cylindrical
tubular.
Dactyls
a finger or the last branchlet of Nitella.
Deciduous
falling off at certain seasons or stages of growth.
Decumbent
reclining or prostrate at the base but with the top or apex erect.
Decussate
in pairs and alternately crossing each other at right angles.
Dehiscent
splits open at maturity by pores, valves or slits to release the contents.
Delicate
fine, not coarse or rough.
Determinate
with a fixed or definite limit, an inflorescence where the central or uppermost flower opens first.
Dichotomous
forked or divided into two.
Dioecious
male and female flowers on separate plants, unisexual.
Diploid
the state where the chromosome number is 2N, after fertilization and resulting from growth of the zygote.
Diplostichous
in two rows or series.
Disc
flat central part of the inflorescence of Asteraceae, a flat circular structure.
Discoid
having a disc or a head.
Disjunct
not continuous, with large gaps in the distribution.
Dissected
finely divided into filiform or narrow segments, no broad blade.
Distal
the farthest away or a far away part relative to the axis.
Distant
far apart, well separated, not contiguous.
Distichous
in two vertical ranks producing leaves in two opposite rows.
Diurnal
opening during the day and closing at night, the daily light and dark cycle.
Dorsal
the back or outer surface facing away from the axis.
Ellipsoidal
egg shaped.
Elliptic
oblong with rounded ends, longer than wide and rounded.
Elongate
not rounded, one dimension, usually between the petiole and the apex, is considerable greater than the other dimension.
Embedded
buried in and surrounded by the matrix tissue.
Emergent
sticking up out of.
Emersed
raised up out of the water.
Endemic
occurs in only the one limited region or area.
Endocarp
the usually woody inner layer of the pericarp or seed coat.
Endodermis
a cell layer with thickened cell walls separating the vascular bundles from the aerenchyma, functions to control water movement laterally in the stem.
Entire
a continuous even margin with no teeth, projections or incisions.
Ephemeral
short-lived, evanescent, usually less than one day.
Epidermis
the thin outermost cell layer separating the plant from its environment.
Erect
upright.
Estuary
the zone where marine and fresh waters meet and mix on a diurnal cycle, brackish.
Estuarine
found in estuaries.
Eutrophic
with high nutrient levels and thus dense plant and algal growth.
Exstipulate
without any stipules.
Facultative
may live under one set of conditions but can also life under another set, facultative aquatics can live under water but can also live on land, usually in wet habitats.
Falcate
sickle shaped, curved, arched.
Family
related, a presumably evolutionarily related group of genera, the next higher classification level above the genus.
Fascicles
bundles, tufts or clusters.
Fellfield
an alpine area with dwarfed, scattered plants.
Fen
level, wet, humus rich, alkaline to neutral, peaty area. with a vegetation cover dominated by sedges.
Fern
non-flowering, non-thalloid plants with a large laminate leaf and sporangia on the leaves.
Ferruginous
rusty red in colour.
Fertile
capable of sexual reproduction, bearing the organs of sexual reproduction.
Fibrous
tough stringy tissue.
Fiddlehead
young stem apex of ferns which are coiled in the bud.
Filament
the stalk of the stamen which bears the anthers, a thin hair-like structure.
Filamentose
thin and hair-like.
Filiform
thread-like or filamentous.
Fimbriate
with a fringed edge of coarse hairs.
Flaccid
limp, not rigid.
Floating
buoyant and either on the surface, just under the surface tension or free in mid-water.
Floral
associated with, or part of, the flower.
Flower
a modified spore-bearing branch, an axis with stamens and/or pistils and often petals and/or sepals.
Flowering plant
a plant which has flowers and produces seeds in a fruit.
Foliate
having leaves.
Follicle
a dry one-celled capsular fruit which dehisces by a longitudinal slit on one side.
Forked
branched into two.
Fringed
a border of coarse hairs.
Frond
the leaf of a fern, palm or liverwort.
Fruit
the structure which develops from the ovary of flowering plants after fertilization, with or without other allied structures formed from other parts of the plant.
Funnel-like
shaped like a funnel, wide at one end and tapering to narrow or constricted at the other end.
Furcate
forked, branched.
Fused
united into one structure.
Fusiform
spindle-shaped, broad in the middle and tapered towards both ends.
Gamete
reproductive cell prior to fusion to produce a spore or zygote, egg or sperm.
Gametangia
the cells or structures in which gametes are produced.
Gamopetalous
a corolla with the edges of the petals wholly or partially united.
Gelatinous
jelly-like.
Geniculate
bent abruptly like a knee or elbow.
Genera
plural of genus.
Genus
composed of evolutionarily closely related species, a unit of classification one step up from the species.
Glabrous
without hairs, bristles or scales.
Glands
in Potamogeton these are a pair of small round, white or yellowish swellings on the side of the stem at the base of the stipules.
Glaucous
covered with a whitish or bluish waxy powder that readily rubs off.
Globose
spherical.
Glochidia
a hair-like appendage with a hooked tip formed on the spore mass of Azolla.
Glume
a chaffy bract at the base of the spikelets in grasses, a scale which makes up the calyx and corolla of grasses.
Grain
fruit of grasses where the ovary wall adheres to the seed as a covering.
Grasslands
lands which develop primarily grasses as the vegetative cover due to the prevailing climate and rainfall.
Habit
the characteristic mode of growth and resulting appearance.
Habitat
the place or type of site where a plant normally grows.
Haploid
the state where the chromosome number is 1N as in sperm and eggs before fertilization.
Haplostichous
one row of cortex cells to each branchlet or bract cell of Chara.
Hard water
normally this means high in calcium and magnesium carbonates and also with a high or alkaline pH.
Hastate
arrowhead shaped with the basal lobes turned out at right angles.
Head
dense round inflorescence of sessile flowers or a close terminal collection of flowers surrounded by an involucre in the Asteraceae.
Helicoid
spiraled.
Herbaceous
non-woody annual plants, may have perennial roots or rhizomes.
Heteroclemous
having leaves of different form, shape or perhaps function.
Hierarchical
a classification scheme where each lower level is completely included in, and subordinate to, the one above.
Hirsute
hairy, usually with stiff or coarse hairs.
Homeoclemous
arising from the same germ layer or tissue.
Horsetails
plants in the non-flowering plant genus Equisetum.
Hyaline
colourless, glass-like.
Hypanthium
the tube of the receptacle on which the petals, sepals and stamens are borne.
Hypogynous
with the floral parts borne at the base of or below the free ovary and not attached to the calyx.
Imbricate
partially overlapping like shingles on a roof.
Imperfect flower
flowers with only female or male parts but not both.
Incised
sharply and deeply cut on the margin.
Indeterminate
not limited or stopped by the development of a terminal bud.
Inferior ovary
an ovary with the calyx tube adnate or fused to it and the petals, sepals and stamens inserted on it.
Inflated
swollen, with a convex bulge.
Inflorescence
the arrangement of flowers or a stem or axis, a cluster of flowers or a single flower.
Inner face
the side of the leave or other structure which faces the portion of the stem or axis above its point of attachment; for a leaf this is the top or dorsal surface, for a petiole the portion in the axil.
Interlacunar bundles
vascular bundles found between the spaces or gaps.
Internodes
the spaces or gaps between the nodes or leaf attachment points on a stem.
Inundate
cover with water.
Involucral
cluster of modified leaves at the base of a flower cluster or head.
Keel
a prominent ridge, boat shaped petals of legumes or the glumes of some grasses.
Krummholz
stunted tree growth in alpine regions, elfin wood.
Lacerate
torn irregularly and deeply.
Lacunae
depression, cavity or airspace.
Lacustrine
living in or beside lakes and ponds.
Lake
more or less permanent, natural, generally large and deep body of standing fresh water.
Lamina
the broad, expanded, blade portion of a leaf.
Lanate
covered in fine, long hair, woolly.
Lanceolate
shaped like a lance, longer than wide, widest at the middle and tapered to a sharp point.
Lateral
on or from the sides as opposed to the base or apex.
Lax
open and widespread as opposed to compact, limp and drooping as opposed to erect.
Leaf
an appendage from the tip or nodes of the stem, usually comprised of a petiole or stalk and a wider blade, usually green and photosynthetic.
Lenticular
lens or lentil shaped, orbicular and convex on both faces.
Life-form
characteristic form and structure by which a plant is adapted to its habitat.
Ligule
a membranous appendage at the tip of the leaf sheath of most grasses, an elongate triangular stipule-like organ above the sporangium on the leaf of Isoetes.
Limb
expanded part of a leaf, petal, sepal or gamopetalous perianth.
Linear
long and narrow with parallel sides.
Lip
the large projecting lobe of a bilabiate corolla.
Liverwort
a group of the Bryophytes with flattened branching thalli or bilaterally arranged leaves, one layer thick, without a midrib.
Lobed
a rounded division where the separation is about half way to the axis, much deeper than teeth.
Longitudinal
lengthwise, parallel to the long axis.
Lowland
this encompasses the low elevation coastal strip and the islands along the coast.
Margin
the edge or rim, especially of a leaf.
Marginal
on the margin or edge.
Marine
in the ocean.
Marl
calcium carbonate precipitation on the surface of plants growing in hard water.
Marsh
soft wet land periodically covered wholly or partly with water and supporting emergent herbaceous vegetation.
Matted
closely intertwined vegetation with roots and rhizomes intermixed usually appressed.
Megaspore
the large spore which gives rise to the female gamete, the larger meiospore.
Meiosis
the nuclear division stage where the chromosome number is reduced from diploid to haploid.
Meiospore
the spore produced by meiosis with reduction in chromosome number from diploid to haploid.
Membrane
thin expanded tissue covering, separating or protecting a cell, organ or tissue.
Membranous
like a membrane or composed of membranes.
Merous
the number of like parts
Micron
there are 1,000,000 microns in a meter or 1,000 microns in a millimeter.
Microspore
the small spore which gives rise to the male gamete, the smaller meiospore.
Minute
very small and inconspicuous.
Monoecious
stamens and pistils in separate flowers on the same plant.
Montane
this includes all continuous forests in BC except for the coastal lowlands.
Morphology
the form and structure, external appearance.
Moss
the largest and most dominant group of the Bryophytes.
Mucilaginous
slimy secretion.
Mucous
slimy, mucilaginous.
Mucronate
with a broad apex ending abruptly in a sharp tip or spine.
Muskeg
a mossy northern bog,, often with Black spruce and hummocks.
Naked
no covering such as a scale, perianth, pubescence or pericarp.
Native
belonging to a particular place by birth, arising and living in that place naturally.
Naturalized
introduced from elsewhere, not native, but maintaining its position in the habitat in competition with the native organisms.
Nectary scale
on Ranunculus petals there may be a pocket or flap of tissue near the base on the ventral or inner-facing side, it is called a nectary scale.
Node
the joint of a culm, the place on a stem where leaves normally arise.
Nodal
at or associated with the node.
Nodally
occurring at the nodes.
Nut
hard, dry, indehiscent fruit derived from two or more carpels enclosed in a hard or leathery pericarp and usually containing one seed.
Nutlet
a small nut.
Obligate
limited to a single form of life or habitat and unable to survive anywhere else.
Oblong
elongate in one dimension and parallel sided.
Obovate
egg shaped with the wide end distal.
Obscure
poorly developed and barely visible, especially venation.
Obtuse
with a blunt or rounded point.
Oospore
the megaspore after fertilization.
Opposite
leaves arising in pairs at 180 degrees to each other at the same node.
Orbicular
spherical or circular.
Oval
egg shaped, elliptical but not symmetric and wider closer to one end.
Ovary
the enlarged base of the pistil or carpel in which the ovules arise.
Ovate
egg shaped with the wide end basal.
Ovule
megasporangium; the unfertilized cell in the ovary which will become the seed.
O-cells
endodermis cells with a completely encircling pattern of wall thickening so they look like O's.
Parietal
attached to or lying near to and parallel to a wall, placentae arising from the peripheral carpel wall as opposed to axile placentation.
Palmate
lobes or divisions spread from a common center.
Palmately
in palmate fashion.
Panicle
a branched or compound raceme with each branch bearing a raceme, a compound inflorescence with pedicellate flowers.
Papillose
with small nipple-shaped projections.
Parenchyma
undifferentiated tissue with thin cell walls, mostly in leaves, fruit and pith, having large blunt ended cells and involved in carbohydrate storage.
Parted
cleft or divided nearly to the base.
Pedicel
a slender stalk or stem, the stalk of a single flower in a flower cluster or inflorescence.
Pedicellate
having pedicels.
Peduncle
the primary stalk supporting an inflorescence, which may be a single flower.
Pedunculate
having a peduncle.
Peltate
a rounded leaf blade with an entire margin and the petiole attached near the center of the ventral surface of the blade as opposed to marginally.
Penultimate
last but one or second from the end.
Perennial
a plant which lives for more than two years, the top may die or go dormant but the roots remain.
Perfect flower
a flower that has both male and female parts.
Perianth
the calyx and corolla collectively, the outer envelope of a flower.
Pericarp
the mature ovary wall or the wall of the fruit or seed developed from the ovary wall.
Perigynium
the modified leaves surrounding the ovary as in the inflated sac or utricle in Carex.
Perigynous
with floral parts adnate to the perianth and therefore around the ovary instead of at its base.
Petals
the modified, usually coloured and showy, leaves of the corolla, the inner of the two perianth whorls.
Petiolate
having a petiole.
Petiole
the stalk which attaches the leaf blade to the stem.
Phloem
vascular tissue which transports food.
Phyllodes
expanded petioles modified in form and structure and functioning as leaf blades.
Pinnate
veins or leaflets paired on opposite sides of a common vein or stem in a feather-like arrangement.
Pinnatifid
pinnately cleft to the middle or deeper into segments.
Pistil
the seed bearing organ, ovary, style and stigma., one or more carpels.
Pistillate
referring to, or of the pistil.
Pithy
central core or cavity of a stem, may be hollow and empty.
Pitted
with small depressions or indentations.
Placenta
the part of the ovary wall to which the ovules are attached.
Pond
a small shallow, natural or man-made, body of standing water, usually permanent, rarely seasonal in contrast to the larger, deeper and permanent lake.
Pool
portion of a stream with deeper water and reduced current, small standing water areas, permanent or seasonal, in marshes, flood plains and other low areas subject to inundation.
Proliferous
producing vegetative offshoots.
Prostrate
hugging the ground, creeping and flat.
Pubescent
hairy or downy.
Punctate
covered in small dots, glands or holes.
Puncticulate
minutely or finely punctilate.
Punctilate
with small dots or glands, often in depressions.
Pyriform
pear shaped.
Quillworts
species of the non-flowering genus Isoetes.
Raceme
an inflorescence composed of pedicellate flowers arranged on an indeterminate axis where the lowermost flowers bloom first.
Racemose
having racemes.
Rachis
the main flower stem to which the outer parts are attached, the axis of a compound leaf, spike or raceme, the main ribs of a frond.
Radial
arranged like spokes on a wheel, all symmetric with the center.
Ranks
rows or series.
Receptacle
the enlarged end of the flower stalk or peduncle which bears the flowers in the Asteraceae.
Reclining
turned or bent downward, leaning or sprawling on something else for support, not erect and self supporting.
Recumbent
lying down, prone on the surface, not erect.
Recurved
drooping or bent back on itself.
Reflexed
bent or turned downward.
Remote
far apart or far away from the base or apex, farther apart than usual.
Reniform
kidney shaped.
Reticulate
net like, netted.
Rheophyte
growing in rapidly running water.
Rhizomatous
having rhizomes.
Rhizome
a thick, prostrate, subterranean stem producing roots and aerial shoots.
Rhombic
diamond shaped.
Rhomboid
having a rhombic shape.
River
large, usually permanent, channel of flowing water.
Robust
rough, strong, vigorous, healthy.
Roots
the usually subterranean, absorptive, anchoring and storage organ in plants.
Rosette
a dense, flat, imbricated cluster of leaves, usually at the base of a plant.
Rugose
coarsely wrinkled, uneven, rough.
Sac
sack, bag or pouch.
Sagebrush
aromatic shrubs of the genus Artemesia, (Asteraceae), in dry, often alkaline plains and rolling hills.
Sagittate
arrowhead shaped.
Scale
small appressed bract or leaf-like structure often found on turions, rhizomes and bulbs.
Scape
a naked or leafless flower stalk arising at or below ground level.
Scapose
having a scape.
Schizocarp
a dry compound fruit which splits at maturity into single-seeded segments called mericarps.
Sclerenchyma
rigid strengthening tissue composed of thick-walled cells often in the shape of fibres.
Sclerenchymatous
composed of sclerenchyma.
Seasonal
occurring at a particular part of the year.
Sediment
the soil on the bottom of lakes, ponds, rivers and streams; the soil deposited underwater, depositional material.
Segments
portions of a leaf which is deeply lobed but not divided into two leaflets.
Sepaloid
sepal-like.
Sepals
the individual parts of the calyx, the whorl of floral parts outside the petals.
Septa
wall or partition.
Septate
having septa.
Serrate
saw-toothed with teeth pointing towards the apex.
Serrulate
small serrate teeth.
Sessile
without any stalk, attached directly.
Sheath
the base of a leaf surrounding the stem at the node.
Sheathing
covering or enveloping, wrapped around, coating.
Shrub
woody perennial with several stems, smaller than a tree.
Sickle-shaped
crescent shaped, curved, in an arc.
Silique
a long slender capsule of two carpels in the Brassicaceae; an elongate two-valved capsular fruit with two parietal placenta, dehiscent.
Simple
not branched, divided or compound, single.
Sinus
the gap formed by leaf lobes.
Slough
a sluggish, shallow channel filled with water, a slow-moving branch of a river with one end connected to the mainstem, overflow channels and side channels of streams and rivers with slow flows, seasonally flowing but permanently filled channels.
Soft water
usually-low in calcium and magnesium carbonate and low in pH, acidic.
Solid
a stem with no space in the middle but tissue all the way to the centre.
Solitary
found alone and not in a group, association or cluster.
Sori
plural of sorus.
Sorus
a cluster of sporangia with a cover over it on the lower surface of fern leaf pinnae.
Spadix
an inflorescence consisting of a fleshy central column with partially embedded stamens below and pistils above and surrounded by a showy spathe, typical of the Araceae.
Spathe
the leaf-like, often coloured, bract subtending the spadix in the Araceae.
Spathulate
spatula-shaped, oblong with an attenuate base.
Species
the lowest classification level, mutually inter-fertile individuals which are much alike and distinct from other species.
Spicate
having spikes.
Spicules
a small spike or prickle, a small pointed appendage.
Spike
an inflorescence in which the flowers are sessile on the sides of a long common peduncle or rachis.
Spikelet
a small spike.
Spine
a thorn or sharp process, rigid, without vascular tissue.
Spores
reproductive body of non-flowering plants, a single cell not an embryo.
Sporocarp
a multicellular organ in which spores are produced.
Sprawling
creeping and spreading out over the surface and on any supporting structures, not erect.
Spur
a tubular elongation of the base of a petal or of a gamopetalous corolla.
Stalk
an elongate above ground support structure to which organs are attached.
Stamens
the pollen bearing organs in a flower.
Staminate
the male flowers or plants which have stamens and produce pollen but no pistil or ovary.
Staminodia
imperfect organs resembling stamens and in the normal location of stamens which are transitional between stamens and petals.
Stem
the main axis of a plant which bears the leaves and flowers.
Steppe
this includes the interior sagebrush and grasslands of the Columbia, Thompson, Okanagan, Kootenay and Flathead river valleys in southern BC and the Fraser, Thompson and Upper Peace river plateaus.
Sterile
not fertile, flowers without pistils or stamens, flowers with only stamens.
Stigma
the tip of the pistil which is receptive to pollen grains and on which they grow.
Stipular
like stipules.
Stipulate
having stipules.
Stipule
a leafy appendage at the base of the petiole, usually one on each side, a basal appendage of a petiole.
Stipulodes
a one-celled organ, in one or more rows, subtending the branchlets in Chara.
Stolon
a modified above ground propagating stem creeping and rooting or arching and rooting at the tip, a runner.
Stoloniferous
having stolons.
Stomates
openings surrounded by guard cells found in the epidermis and controlling gas exchange in to leaves and stems.
Stream
a small river, narrower and shallower, formed by natural forces and having a definable bed and banks, seasonal or permanent flow.
Striation
furrows, grooves, channels; parallel stripes or marks.
Style
the narrow neck above the ovary which has the stigma on top.
Sub
a prefix meaning nearly or almost.
Subalpine
this includes all lands between the Montane zone and the upper limit of conifers as an upright tree.
Submersed
this means the same as submerged and is now used primarily in botanical contexts related to aquatic plants.
Subtended
to enclose in its axil or to be under or opposite to.
Subterranean
under the surface of the sediment or soil.
Superior ovary
an ovary free from the calyx all the way to the base; an ovary on top of a receptacle with the petals and stamens hypogynous or perigynous.
Suture
a line of fusion, a line along which dehiscence may occur.
Swamp
a flat wet area covered in standing water and supporting a growth of grasses, shrubs and trees, thin layer of organic soil, not peaty.
Swollen
distended, bulging, convex, enlarged.
Sympodial
the main axis stops growing and a lateral takes over, this occurs successively.
Synonyms
a scientific name which has been superseded, or is by the rules of nomenclature not valid.
Tapered
getting progressively narrower.
Terete
cylindrical and tapering.
Terminal
at the end, the last one.
Ternate
in threes.
Thalli
plural of thallus.
Thalloid
having a thallus.
Thallus
a plant body not differentiated into roots, stems and leaves, the entire body of algae or fungi.
Tidal flats
area diurnally inundated by the sea.
Tier
row, rank or layer.
Toothed
with teeth, dentate.
Transverse
crosswise, as opposed to lengthwise.
Tree
woody plant with one main trunk and a distinctly elevated canopy.
Trichotomous
three branches arising from the same point.
Trifid
divided about halfway down into three lobes or parts.
Trifoliate
a compound leaf divided into three leaflets.
Trigonal
being trigonous.
Trigonous
three-angled with three convex faces, three-cornered.
Triplostichous
with three rows of cortical cells to each branchlet or bract cell in the Characeae.
Truncate
blunt, cut off abruptly, squared.
Tuber
a short, thick rhizome with many buds, a subterranean stem shorter and thicker than the root stock.
Tubercles
a wart-like or knob-like excrescence, the bulbil of Characeae, the persistent base of the style in Cyperaceae.
Tuberous
having tubers.
Turgid
swollen, tight, distended.
Turions
a swollen perennating bud of water plants, winter bud.
Ultimate
last, most remote, end of the line, furthest away.
Umbel
a flat-topped inflorescence in which the pedicels are of equal length and arise from a common point.
Umbellate
having umbels.
Undifferentiated
not distinct or separable, the same.
Undulate
wavy.
Utricle
an achene with a loose involucral covering.
U-cells
endodermis cells with wall thickening on only three sides to give them a U-shaped appearance.
Vascular bundles
strands of xylem, phloem and sometimes sclerenchymatous supporting tissue. found in the stems of vascular plants.
Vegetative
concerned with growth and development as opposed to reproduction.
Vein
a strand of conducting tissue in the leaf.
Veinlet
a small vein.
Ventral
the upper surface of a leaf, on the part of an organ nearest the axis, the inner face.
Vernal
occurring in the spring and usually gone by summer.
Warty
a horny excrescence or protuberance.
Weedy
with rank and profuse growth, vigorous.
Wetland
land which is always, or usually wet or inundated, the water table is high and in the root zone, high organic productivity
Whorled
with more than two leaves or organs around a node.
Winged
with a thin extension or expansion around the object.
Woody
having secondary xylem and other structural and supporting fibrous tissues.
Xylem
the part of the vascular bundle which conducts water and provided mechanical strength.
Zygomorphic
bilaterally symmetrical.
Zygote
the cell resulting from the fusion of two gametes, the first cell of the new generation in sexual reproduction.
Return To The Table of Contents

APPENDIX: COLLECTING AND PRESERVING AQUATIC PLANTS

Introduction
The collection of aquatic plants is often done as part of ecological or impact studies, both as a record of conditions at a given time for comparison with prior or later conditions, and as a necessity when the collectors are not able to identify the specimens in the field and need to send a specimen to an expert. These specimens are a valuable scientific records and their collection and subsequent handling should be done with care so that the time and expense that has gone into their collection is not wasted. Herbaria exist for the purpose of long term care and storage of the specimens and uniform standards have been set up for the mounting, care and storage of plant specimens. These standards should be followed so that the plants will become valuable scientific specimens for more than the specific purpose for which they were collected. In addition, their storage in a long term facility like an herbarium will make them accessible to subsequent researchers for other uses. Herbaria provide a permanent record of what was found and if identifications need to be rechecked the specimens are available. Even when the major thrust of the work is for biomass studies or tissue analyses, representative specimens must still be collected and saved as vouchers of what species were analyzed or studied.

There is a good manual published by the BC Ministry of Forests (Aikens, 1996) which is recommended as a reference for collecting, preserving, processing and storing botanical specimens. Most of that information is not repeated here. This appendix is concerned only with the idiosyncrasies of certain aquatic plants which require special handling in order to make good herbarium specimens.

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General Specimen Handling Procedures
Plants are mounted on white card stock, about 11 by 16 inches and stored in Herbarium Cabinets made for this purpose. These cabinets have insect-proof tightly-sealed doors, and shelves which accommodate these standard-sized mounting boards. This uniformity facilitates exchange of specimens between institutions and a common design of storage cabinets and facilities. One should assume that a specimen is both permanent and valuable; treat it as such when you collect it, when you are processing and storing it and when you are handling it at a later date. Many specimens in herbaria around the world are hundreds of years old and are of great value in documenting changes in the habitats of areas, and in the study of the ongoing process of plant evolution.

For terrestrial plants, where the plants are rigid and can be mounted dry, most good quality white card stock is acceptable. However most submersed plants do not have structural supporting tissues, they rely on the water for support, and they must be floated onto the card stock. Therefore a paper which remains dimensionally stable after wetting and subsequent drying is required. Most ordinary papers, after being soaked, will wrinkle upon subsequent drying, even if they are kept pressed during the drying process. Ask your paper supplier for a card stock which does not react this way; they are available but their trade names change from time-to-time and supplier-to-supplier.

Return To The Appendix
Collecting
There are a number of aquatic plant collection methods which have been used. The one to use in a given situation depends upon the specific situation and the reason for the collection.

Picking the whole plant by hand is the best method for getting an entire plant in undamaged condition, particularly for preservation as a herbarium specimen. In shallow water this is readily done by wading if the bottom is firm, or by leaning over the side of a canoe where the bottom is too soft for wading. In deeper water snorkeling is the best method. The closer and clearer view of the bottom will often allow one to see small species that were not visible from the surface. In still deeper water SCUBA, or surface-supplied-air diving may be necessary. If there is any wave action, surface ripple or glare, it is difficult to see the bottom from the air; this problem is eliminated when one is underwater.

Rakes or cultivators with long handles can be used to uproot and bring up plants when working from a boat. Cultivators with four long, closely-set prongs are better for uprooting plants but, for small species like Isoetes, it may be difficult to bring the plants to the surface. An Ekman dredge will also bring up small species from deep water if the sediment surface is not too hard. In deep water where visibility is poor one can get a random sample of some of the plants which are present by dragging an anchor from a boat. The plants are not in very good shape and the sample is not necessarily representative of all the species present. Usually all that is collected are fragments of plants without roots or rhizomes and small plants like Isoetes will be missed. For sample completeness and specimen quality none of these methods are as good as picking by hand.

Generally the whole plant should be collected. Some groups can not be identified to species without mature fruits or flowers; others need rhizomes, leaf axils or tips. Since submersed aquatic plants do not have to guard against loss of water from their tissues, they do not have waxy or water-repellent cuticles like emergent plants. Do not leave them exposed, even briefly, since they will wither very quickly and become useless as specimens. Keep them in a bag or bucket of water at all times until you are ready to press them. Emergent plants should not be submersed but kept in a bag with a little water in the bottom to maintain a high humidity. It is best to keep each species in its own bag and all the bags from one lake or site together in one large bag.

Some very small plants like the duckweeds do not make very satisfactory pressed and dried specimens, nor is it convenient to collect them into a bag. Small, 20 mL, screw cap vials make good collecting and preservation containers for these plants. Put a little water into the vial to keep the plants moist. Later fill the vial with a solution of 5% formalin, 25% water and 70% ethanol as a permanent preservative. This liquid may need to be replaced after about a month since it will extract chlorophyll and pigments from the plants and become quite dark or opaque. Isopropanol can be used instead of ethanol but ethanol is preferred. There are other better and more permanent preserving fluids which can be purchased or made up and if a great many specimens of such plants will be collected, or if detailed study of the specimens is going to be carried out, then an appropriate preserving solution should be chosen.

Under some conditions it may be necessary to bring back frozen specimens from the field. Some species do not react very well to freezing and will not be suitable for permanent herbarium specimens. However the plants are identifiable and provide distribution records. Put each specimen in its own bag; a tangled mass of frozen plants is difficult to separate without damage.

If you are returning from the field within a day you may bring plants back in their plastic bags and press them later. They will keep quite well overnight in the crisper section of a refrigerator if necessary. Do not keep them too long or the quality of the specimens deteriorates. In general plants should be pressed as soon as possible after they are collected for the best specimens.

A common technique for fruiting plants, where the seeds may be shed on drying, is to collect the seeds, which are often diagnostic, in small paper or cellophane pouches and attach these pouches to the finished herbarium sheet.

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Mounting and Labeling
Generally, for stiff, erect, emergent plants which are similar to terrestrial plants, and those aquatics which do not clump together when taken from the water, no special techniques are required. Lay the plants on the card stock with the roots in the bottom left corner and fold over the tops if they are too tall to fit. Do not cover the label area in the bottom right corner. Spread out leaves and flowers, turn some over so the bottoms can be seen, and try to make a neat and tidy specimen that covers the whole sheet. For small plants fill the sheet with more specimens from the same clump or clone, to show as much variability as possible.

Plants which are not rigid and erect, but clump together or are flaccid, need to be floated onto the card stock and arranged neatly to keep them from matting or clumping. Floating may be done in motel bathtubs or shower stalls, in 14 by 20 inch photographic trays or in lakes and ponds. It will be difficult in lakes if there is any wind or waves. Do not take plants to a different lake to float them onto the card stock; you risk spreading weeds from lake to lake. Using a tray on a picnic table, at a site with running water, is an ideal mounting and pressing situation, as is the tailgate of a truck with a canopy. Float the specimens of one species on the water in a tray and slide the mounting board under the plants.

Start by slowly lifting the bottom of the card stock out of the water at the root end and arranging and spreading the plant as you continue. Once a portion is out of the water it will stay in place. Some, but not all, plants will allow a limited amount of rearranging once they are out of the water. Hold the card stock with one corner down and let most of the excess water drain off. This will be tricky with small plants since you will be managing several specimens simultaneously.

After arranging the aquatic plant on the card stock a piece of heavy blotting paper is placed on top of the specimen to help dry the plant quickly. These blotters are re-usable and are usually about 12 by 18 inches in size. The package of the card stock with the plant and the blotter is wrapped in a newsprint folder while in the drying press; this newsprint is also re-usable. It is usually 12 by 36 inches in size and folded in half to form a folder in which the mounted plant is placed. Field notes are often written on this newspaper but for aquatic plants, where the specimens stay on the card stock permanently, notes should be written on the top side of the card stock in the bottom right-hand corner where it will later be covered by the permanent label. This way the label data stays with the specimens. The size of this label is usually about 5 inches wide by 3 inches high; confine your field notes to a space smaller than this so the subsequent label will completely cover them. Write the notes on the card stock in pencil and do so before you float the plants onto the card. You will not be able to write on the card once it is wet.

The wrapped packages of plants on card stock with a blotter and a newsprint folder are put into a plant press with a piece of corrugated cardboard separating each package. This re-usable cardboard is usually 12 by 18 inches and all the corrugations should run in the same direction so that air flow through the press is facilitated. Quick drying under pressure is needed; drying should take place within several days to prevent fungal growth and rotting, and to preserve colors and shapes as much as possible. If you will be in a laboratory or herbarium the same day the plant presses may be dried in a proper plant drier or a forced draft oven at 40 degrees. In the field use motel hot air registers, baseboard heaters, or hair dryers to move warm air through the corrugated cardboard. If the weather is dry put the plant press on the roof of the truck and allow air to blow through the corrugated cardboard as you drive from site to site. As the plants in the presses dry it will be necessary to re-tighten the presses periodically, at least daily, to maintain pressure and keep the plants flat.

The label information must include at least the date, the name(s) of the collector(s) and the name and specific location of the lake or water body. Latitude and longitude, or UTM or military grid references are best since they are unique. Names are neither unique nor permanent and some towns and stations are ephemeral. Will the location data from BC you use today mean anything to someone from Australia 100 years from now? It should also include as much ecological data as possible including other associated plants, location in the lake, specific habitats and rarity. When you put the plant press together have all the mounting card facing the same way, all the tops at the same end, all the newspaper sleeves opening to the same side (preferably the right), and all the specimens from one lake or site together as a group. This greatly facilitates the subsequent job of taking the press apart, entering the data and re-assembling the press for the next trip.

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Emergent and wetland plants
Some plants are emergent and erect, or if submersed are rigid and hold their shape when taken from the water. These do not require any special handling and may be mounted dry as with any terrestrial plants. Glyceria with leaves floating on the surface of the water may sometimes be difficult and require floating. In some cases plants in hard-water lakes become encrusted with marl and are rigid or stiff enough to be mounted dry too, although they would normally need to be floated onto the mounting sheet. Examine each specimen to determine whether or not floating is required. There are a few totally submersed species which are rigid and self-supporting. Many of these do not have leafy stems; instead their roots and leaves arise directly from a swollen base. These rigid species include Isoetes, Lobelia dortmanna, Subularia aquatica, Lilaeopsis occidentalis, Crassula aquatica, and often the Characeae and Marsiliaceae. The wetland and emergent plants rarely require any special treatment.
Return To The Appendix
Small floating plants
Small floating plants in Part 1 of the General Key may be floated onto the mounting board or mounted dry but should also be put into vials and preserved wet. These include specimens of Salvinia, Azolla, Lemna, Spirodela, Wolffia, Wolffiella, Riccia, Ricciocarpus, Utricularia gibba and Utricularia minor. These small, floating plants, of which many specimens will fit into one 20 mL vial, may also be found growing on damp muddy banks which are shaded from the direct sun and stranded by declining water levels. Since they are small and freely floating they congregate in sheltered areas and are rare in open water sites.

In large lakes they will be found at the down-wind end among dense beds of other vegetation and woody debris along the shore. They are more often found in ponds, ditches, sloughs, embayments and other protected waters which are rich in nutrients, but with little, if any, fetch or wind exposure. They will desiccate quickly if left out of water for even a short time; collect them directly into a vial or small bag containing some water. Once mounted and dried many of these plants adhere permanently to the mounting board and cannot be removed; thus they must be mounted directly onto their permanent mounting board. They may not be dried first between newsprint and then transferred to the mounting board as is done with terrestrial and wetland plants.

The duckweed Lemna trisulca is usually found submersed and lying on the bottom; the other duckweeds, Lemna minor, Wolffia columbiana, Wolffia borealis, Wolffiella floridana and Spirodela polyrhiza, float on, or at the surface. Wolffia and Wolffiella are very small and almost featureless, even at 10X magnification. The common name is watermeal and they often look like pollen grains floating on the surface. They are rarely recognized and collected, but are probably more common than recorded, and usually found growing mixed with the other duckweeds.

The bladderworts Utricularia minor and Utricularia gibba, are submersed but are usually found near the surface and often in tangled mats or wrapped around other species of aquatic plants. The other species include two aquatic liverworts, Riccia fluitans and Ricciocarpus natans; three aquatic ferns, Azolla filiculoides, Azolla caroliniana, Azolla mexicana and rarely another aquatic fern, Salvinia, aquarium plants which may be dumped but have not yet been shown to overwinter successfully in BC. The ferns are larger and make good herbarium sheet specimens but since microscopic examination of the spores is required for positive identification, preserving some specimens in a vial is useful.

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Submersed flaccid and dissected-leaf plants
These plants usually grow either underwater, or floating at the surface with only their flowers emergent. Some species are rooted in the bottom, while others are free-floating. They may be sufficiently stiff to be pressed dry but they generally need to be floated onto the mounting board. Submersed specimens of Sium sauve and grasses in the genus Glyceria are in this group. Occasionally some species in this group may become so encrusted in 'marl', when growing in hard water, that they are rigid enough to mount dry but they should have a blotter added to the press.

Ceratophyllum demersum and Myriophyllum sibiricum are examples of plants which may have marl encrustation. Terrestrial specimens of Hippuris vulgaris, Ranunculus, Myriophyllum,

Polygonum and Potamogeton are sometimes found. They are rigid and firm enough to mount dry. Elodea may also grow in a dense, short-internode form which may be mounted dry.

This group of species is treated together because they tend to collapse or clump together when removed from the water and thus they need to be floated onto the mounting sheet. As a rule the whole plant should be collected, roots, stems, leaves, flowers and fruits. Once mounted and dried many of these plants adhere permanently to the mounting board and cannot be removed without damage; thus they must be mounted directly onto their permanent mounting board. They may not be dried first between newsprint and then transferred to the board as is done with terrestrial and wetland plants.

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Plants requiring special handling
Brasenia schreberi is a floating-leaf species usually found a little deeper than Nuphar. Brasenia leaves are peltate (the petiole is attached in the center of the blade), reddish-green above and red below. The flowers are small, inconspicuous and reddish. Brasenia has a rhizome but all that needs to be collected is the apical portion of the stem with several leaves, the bud and preferably the flowers. All the underwater portions of Brasenia are covered in a coat of mucilaginous or gelatinous material of variable thickness. When this dries the plants are permanently glued to whatever they are in contact with while being pressed. You must use a sheet of smooth non-porous material such as polyethylene, wax paper or saran wrap between the plant and the blotter when pressing this species. Turn several of the leaves over to show the undersides as this will not be possible later.

Callitriche may be found in up to 1 or 2 meters of water in slow creeks or lakes, but is most often found in marginal habitats, in ditches, or stranded on wet mud. In deeper water, plants are usually rooted in the bottom, have a thin leafy stem in the water column and a rosette of dark green leaves in a cluster at the surface. In ditches they may form very extensive mats covering the entire water surface. Diagnostic characters include the details of leaf-apices, leaf-venation, the junction of the leaves with the stem, and, most importantly, the morphology of the mature fruits. Try to collect fruiting specimens.

Carex may have extensive rhizomes which are often diagnostic. Collect a piece of this rhizome with each emergent plant. Carex are numerous and widespread throughout BC. Most grow in wet, seepage habitats, though some inhabit dry sand-dunes, and some are marginal aquatics. Mature fruits are usually required for positive identification in this taxonomically difficult group.

Ceratophyllum do not have roots but may be anchored on the bottom. Usually they float freely in large dense mats at the surface. In eutrophic waters Ceratophyllum demersum can become a serious nuisance. Ceratophyllum echinatum generally grows well submersed and is more difficult to find and collect. They are superficially very similar but may be readily distinguished by the spines on their fruits which are hidden amongst the foliage near the surface. Try to collect some of these fruits in late summer.

Chara, Tolypella and Nitella are large algae anchored to the bottom, growing in clumps or mats, and completely submersed in lakes and creeks; some grow in quite deep water. Chara has a strong, unpleasant odour when brought out of the water. When fruiting many small orange or red structures may be seen among the branches. The species are difficult to distinguish and generally require a dissecting microscope. They all have a tendency to stick to the blotter and thus before the blotter is put down pieces of polyethylene or saran wrap should be placed over the plants. This will peel off readily once the press is thoroughly dry.

Elodea species are widespread in a variety of habitats and may become weeds in eutrophic conditions. They may have long internodes with large gaps between leaves or be very compact. Since these are favored aquarium plants, they may be introduced to a number of lakes. Flowers are very small, white, and on the ends of very long thin stipes so as to reach the surface; they are rarely found or collected, and if present fall off readily and are lost. Take special care to save these flowers and their stalks.

Egeria is very similar to Elodea and should be treated the same way. It is a rare introduced species, and a weed, known from only a few lakes in BC. Hydrilla, a very serious weed, has not been found in BC yet. It is similar and should be treated the same as Elodea. It has small tubers buried in the mud; collect some of these tubers. Do not spread Egeria or Hydrilla from lake to lake!

Eichhornia crassipes, the water hyacinth, is a large floating tropical weed which is readily available and often planted in BC but has not yet been known to overwinter. The petioles are swollen and serve as floats and may be a problem in mounting. If necessary section the float and make a note on the label.

Equisetum, the horse-tails, are marginal in lakes, or found in shallow ponds and wet seepage areas. The stems are segmented and hollow and usually do not have any branches. The fruiting structure, a 'cone', is apical. The 'cones', the presence or absence of branches, and the details of the bracts at the joints are all diagnostic. In addition some species have separate fruiting and vegetative stems which are morphologically distinct and often mature at different seasons.

Fontinalis antipyretica is an aquatic moss often found attached to rocks or logs around the margins of lakes and in streams. It may grow quite deep, or in habitats left exposed in summer low-water conditions. In the latter case it dries out and becomes dormant for the summer. This plant has not been found in BC. waters with a pH higher than 8.1 since it can not utilize bicarbonate as an inorganic carbon source for photosynthesis but relies on dissolved C02. Fontinalis antipyretica, and other aquatic mosses, hold a great deal of water and should have an extra blotter beneath the mounting board.

Heteranthera dubia is submersed, or floating just at the surface, in quiet water of lakes, streams and ponds. The flowers are small and pale yellow but rarely seen in BC; the plant can be difficult to identify without them, look for them. Although rarely recognized and collected the species is likely restricted to southern BC.

Hippuris vulgaris grows on exposed mud banks or in very shallow water where it has short, firm, bright green whorls of leaves or in deep water where the leaves are long, limp and brownish. If it reaches the surface in deep water the leaf form changes abruptly at the surface and both leaf types are found on the same plant. The stem is hollow and appears jointed. The emergent portions and the terrestrial plants do not need to be floated onto the herbarium sheet, but the flaccid submersed portions of these plants do require floating.

Hydrilla-See Elodea.

Isoetes are not generally distinguishable to species without microscopic examination of the spores which are found in a pouch at the base of the quill-like leaves. These fully submersed plants may grow in quite deep water. Isoetes grow from a swollen, two-or-three-lobed, base which may be hard to press. With large specimens slice this base into two or three longitudinal sections and press all the slices; small specimens may not require slicing and can be pressed whole.

Myriophyllum all have finely dissected 'feather-like' leaves in whorls around the stem. They may grow on mud banks exposed by receeding water levels, or as deep as 6 meters. Most have flowers on emergent spikes but some have flowers in the axils of ordinary submersed leaves. The genus occurs in a wide variety of habitats throughout BC, although some species have very restricted distributions and specific habitat preferences. Specific identification is often difficult with only vegetative material. Many specimens stick to the blotter and need to be covered with saran wrap or polyethylene.

Nitella-See Chara.

Nuphar are the native yellow waterlilies or cow lilies. They grow from subterranean rhizomes which may be many meters long and 20 cm in diameter. The petioles reach the surface and bear a large floating leaf which may be emergent when water levels drop. The plants also grow on wet mud when water levels drop. Both species have large robust yellow flowers. They grow out to 2 or 3 meters depth. Cut a thin cross-section of the petiole a short distance below the leaf and note whether it is round or compressed. Floral details are required for identification. Remove the conspicuous green and yellow sepals (the petals are small and inconspicuous) from a flower and mount them, note how many there are on the label; also mount a few stamens and note whether they are all yellow or have reddish or purplish markings. The flower is large and thick and needs to be sliced longitudinally to be pressed properly. As the flower parts, especially the seeds, are sticky they should be covered with polyethylene or saran wrap to prevent them sticking to the blotter.

Nymphaea are ornamental water lilies with red, white, pink, yellow or multi-colored flowers. There are a number of "escaped" populations in BC. but most are bought and cultivated by lakeshore owners; be discrete and tactful when collecting Nymphaea. They grow from large subterranean rhizomes and only the petioles ascend to the surface as in Nuphar. The floating leaves may be red on the lower surface and are usually smaller and rounder than Nuphar leaves. The leaf lobes often overlap obscuring the notch. Floral details are required for identification; collect a few each of the sepals, petals and stamens. Note the colors of these flower parts and the approximate numbers of each; note also whether or not the flower is fragrant, the time of day and whether or not the flower was open.

Potamogeton is the largest genus of aquatic plants in BC and the species encompass a lot of variability. The 26 species of Potamogeton in BC grow in a wide diversity of habitats and growth forms. Potamogetons are found in almost all aquatic habitats from marshes, stranded on wet mud, or in up to 6 meters of water. Diagnostic characters in Potamogeton include the fruits, floating leaves, structure of the junction between leaves, stems and petioles, stipules, and nodal morphology. Many are too big to fit on a herbarium sheet since they may surface from as deep as 6 m. Deep plants usually have few submersed leaves, except near the apical portion of the stem.

Some Potamogeton species have floating leaves arising near the stem tip and may have lost all, or most, of their submersed leaves by this time. Collect the upper portion of the stem with flowers, fruits, floating leaves and a few submersed leaves and some rhizome. When pressing these plants make sure that some leaves of each type are upside down and some right side up. One Potamogeton group which can be difficult to distinguish vegetatively, has long, narrow, fully submersed leaves and no floating leaves. They are usually small enough to collect the whole plant and may need to be covered with saran wrap or polyethylene to prevent them sticking to the blotter.

Sagittaria leaves are of little diagnostic value; intact inflorescences with flowers and fruits are required. Do not lose the white petals which usually fall off in the collecting bag. These are usually marginal and shallow-water plants but both Alisma and Sagittaria may also grow in deep water where they have non-surfacing linear leaves, totally unlike their typical emergent leaves.

Scirpus lacustris, the bulrush, is a very widespread marginal species in BC, often forming a complete impenetrable fringe around lakes, ponds and marshes. It often grows in shallow water well out into exposed portions of lakes where its extensive rhizome system stabilizes the sandy bottom. Since Scirpus lacustris is up to 3 m tall it is a problem to press. What is essential is the upper portion of the stem with the inflorescence, though if a small shoot can be found at the apex of the rhizome it could be collected intact.

Sparganium eurycarpum plants can be pressed whole though it may grow rather large. It is the large, hard, globular, spiny fruits which are a problem and longitudinal slicing may be required.

Tolypella-See Chara.

Utricularia intermedia is anchored in the sediment by specialized branches which bear the white bladders but no leaves. These are not visible until the plant is pulled out of the soft mud. They often grow too deep to flower; look for shallow specimens with their emergent yellow flowers.

Utricularia vulgaris may be a very long and large plant, much more than will fit on a herbarium sheet. Start from the apex and fit as much on the sheet as you can, note how much was cut off. The apical bladders may be green, the next ones reddish and the distal ones blackish. Look for the emergent, yellow, snapdragon-like flowers on long thin stalks.

Grasses are often found growing in wet marginal habitats in BC. In most cases leaf-sheaths and mature fruits are required for identification. It is usually best to collect some of the roots or rhizomes as well.

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Biomass Studies
In biomass studies one wants to know how much plant material is present on an area or lake basis. Since plants are not randomly distributed in a lake, the value should be stated for that part of the lake from which the biomass value was produced, or given on an entire lake basis. In all cases an entire, intact, voucher specimen of each species should be collected and put in a herbarium, as a record of what was analyzed. The procedures outlined above should be followed. The studies may produce standing-crop estimates or annual production estimates. The roots, rhizomes and sub-sediment storage organs may be a very significant part of these estimates, well over half for some species, and these are a challenge to collect quantitatively.

Plants should not be allowed to desiccate, but should be blotted dry of water adhering to the surface so that an accurate wet-weight can be determined. Rapid drying to a constant weight, in a forced-draft oven with good temperature control, is necessary for accurate results. This can be a challenge when one has a lot of wet plants to process. Some careful planning and pre-timed sampling is necessary; do not come back to the laboratory with hundreds of kilograms of plants all at once, and only one drying oven available.

Isolating a measured area, sampling all the plants within this area, and none from outside, is not a trivial problem in dense weed beds and deep water. In this worst case it may be necessary to laboriously clear away the plants surrounding an internal area. This would provide a clear working space in which to measure and outline the desired plot, remove all plants outside the boundaries and then harvest the plot quantitatively. This is not easy to do since most deep weed bed plants do not rise straight up to the surface, but are intertwined and spread out as they ascend.

Standing crop estimates tell one how much plant material is present at the moment of sampling, this value obviously depends upon when the sample is taken. Annual production estimates try to determine how much biomass is produced on the site over a growing season. This takes into account losses during the season and material metabolized by the plants themselves.

How to do this without influencing the results, by altering the type and rate of growth by your sampling is a problem. There are no simple, satisfactory solutions and only rough approximations are possible and these entail considerable experimental work.

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Tissue Analyses
Plant tissues may be collected for tissue analyses of metals, pesticides, nutrients, plants products and other parameters, for dry weight to wet weight ratios, or for other laboratory analyses. In all cases an entire, intact, voucher specimen of each species should be collected and put in a herbarium, as a record of what was analyzed. The procedures outlined above should be followed.

For wet-weight to dry-weight ratios one usually needs the entire plant, but this may not always be the case; one should always specify carefully what was taken. In species with extensive rhizome systems and storage tubers it may not be possible to isolate a portion of rhizome or tuber which belongs to a particular stem and its leaves. Representative portions of both parts of the species will have to be analyzed separately. Plants should not be allowed to desiccate, but should be blotted dry of water adhering to the surface so that an accurate wet-weight can be determined.

For analyses of chemicals one may well want to analyze distinct portions of the plant separately to determine where the material is localized in the plant. Roots and rhizomes can be significant repositories and sometimes contain the majority of the standing crop of the species, on a wet-weight or dry-weight basis. If a plant has a significant amount of epiphytic periphyton the analyses may not accurately reflect that of the plant itself. Plants should not be allowed to desiccate, but should be blotted dry of water adhering to the surface so that an accurate wet-weight can be determined. Analyses should probably be done on both a wet-weight and a dry-weight basis. The specific sample handling requirements of the analyses to be carried out, as specified by the laboratory, must be carried out with respect to sample containers, preservatives, shipping times, temperatures and quantities of material.

In some ecological studies a representative sample of known wet-weight is analyzed for its chemical constituents and then these values are applied to the whole lake or ecosystem, by estimating the total wet-weight of the plant that is present as determined by biomass studies. Small errors will be magnified greatly as analyses on small samples are scaled up.

Do several chemical analyses and several biomass sample estimates in order to get an estimate of the variability of your analyses, and thus the range of values within which your ecosystem or lake total may lie.

Plants growing on different substrates and in different water qualities may provide significantly different chemical analyses. There will also be quite different total chemical levels, and different distributions of these chemicals within the plants, during different seasons of the year. Some plant products which one may want to analyze, sugars, starches, nitrogen compounds, photosynthetic products, respiratory intermediates, and enzymes, will also vary markedly, diurnally and by tissue, depending upon whether they are being made, translocated, stored or converted to other forms. Some of this variation will be weather dependent.

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FIGURES

FIGURE 1
EXAMPLES OF DISSECTED UNDERWATER LEAVES
illustrated dissected leaves
illustrated dissected leaves
FIGURE 2
THE PARTS OF A PLANT
illustrated parts
FIGURE 3
ILLUSTRATED GLOSSARY OF LEAF TYPES AND PLANT HABIT
illustrated glossary
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Dr. Patrick Warrington
Water Quality
Water Protection Branch
Ministry of Water, Land and Air Protection
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This page was last updated December 14, 2001