Transcript Powerpoint Version - SHAC Environmental Products

Some Common Algae and Aquatic Weeds
of Canada and U.S.
Basic Identification and Information Guide
Revision Date: November 1, 2004
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Click on the picture that most closely resembles
the algae you wish to identify
(1)
Filamentous
or Planktonic
(10)
Chara spp.
(1)
Nitella spp.
Algae can be generally categorized by the form it takes in water (ex. planktonic,
filamentous, erect), or by algal groups (ex. green algae, blue-green algae etc.)
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Planktonic and Filamentous Algae

Planktonic algae are floating microscope 
plants that are normal and essential
inhabitants of sunlit surface waters. There
are literally millions of floating planktonic
algae that turn pond water shades of green,
blue-green, brown or variations in between.
Planktonic algae that colors the water is often
called a “bloom” or “algae bloom”. Many
species of planktonic algae can be present at
the same time in a water body1.
Filamentous algae are single algae cells that
form long visible chains, threads, or filaments.
These filaments intertwine forming a mat that
resembles wet wool. Filamentous algae starts
growing along the bottom in shallow water or
attached to structures in the water (like rocks
or other aquatic plants). Often filamentous
algae floats to the surface forming large mats,
which are commonly referred to as “pond
scums”. There are many species of
filamentous algae and often more than one
species will be present at the same time1.
Some common
types of planktonic
algae include:
Chlamydomonas,
Chlorella,
Euglena,Closterium,
Anacystis spp., etc.
(1)
Some common
types of filamentous
algae include:
Spirogyra,
Anabaena,
Oscillatoria,
Lyngbya, Pithophora
spp., etc
(1)
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Different Algae Groups
Green Algae: a very large and diverse group of algae (mostly freshwater). Typically
green, but not always. During a bloom, water generally looks greenish in colour.
Some are motile, while others are sessile. Some common Green Algae are shown
below6:
Planktonic forms
Filamentous forms
Blue-Green Algae (Cyanobacteria): Used to be considered algae, but is actually more
closely related to bacteria. A cyanobacteria bloom is obvious when the water turns a
blue-green colour. Some common Cyanobacteria are shown below6:
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Different Algae Groups
Diatoms: Usually yellow-brown in colour, with rigid looking cell walls. Diatoms are
usually sessile and can be numerous in fresh water. Some common diatoms are
shown below6:
Red Algae: Not very common in fresh water, and not always red. Most Red Algae is
marine. Often during a bloom, water will appear brown or reddish. Some common
Red Algae are shown below6:
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Different Algae Groups
Desmids: Fairly common freshwater algae. Many have 2 semi cells that are mirror
images. Some of the very large desmids can be seen without magnification. Some
common desmids are shown below6:
Please click on the link below, then click on ALGAE on the webpage for
further algae information
Pond Identification
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Chara spp.

Chara is often called muskgrass or skunkweed because of its foul, musty almost
garlic-like odor. Chara is a gray-green branched multicellular algae that is often
confused with submerged flowering plants. However, Chara has no flower, will not
extend above the water surface, and often has a “grainy” or “crunchy” texture.
Chara has cylindrical, whorled branches with 6 to 16 branchlets around each
node1.
(1)
Distribution:
Worldwide
(10)
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Nitella spp.

A special kind of algae that grows only in fresh water is Nitella (also known as
stoneworts). They resemble small tress and grow in miniature forests at the
lake bottom; they are known for their unpleasant smell. Nitella is branched
multicellular algae that is often confused with submerged flowering plants.
However, it has no flower and will not extend above the water surface. Nitella
has no odor and is soft to the touch, unlike Chara. Stoneworts are light to dark
green in color with forked, bushy branches 1/16 to 1/8 inches in diameter1.
(1)
Distribution:
(1)
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Worldwide
Aquatic Plants
Click on the category of aquatic plant
that you wish to identify
Floating
Submersed
Emergent
(9)
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Floating Aquatic Plants
Click on a picture to select a plant
Duckweed
Watermeal
Water Hyacinth
White Water Lily
Watershield
Yellow Water Lily
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Duckweed – Lemna spp., Spirodela spp.

Common Duckweed is a very small light green free-floating, seed bearing plant.
Duckweed has 1 to 3 leaves - 1/16 – 1/8 inch in length. A single root hair protrudes
from each tiny leaf. Giant or big duckweed is still relatively small 1/16 to 1/4 inch with
1 to 4 leaves with three or more roots hairs protruding from each leaf. Duckweeds
tend to grow in dense colonies in undisturbed waters or ponds, and can be
aggressive invaders of ponds. These plants should be controlled before they cover
the entire surface of the pond1.
Distribution:
Worldwide
(1)
(4)
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Watermeal - Wolfia spp.

Watermeal is a very tiny (<1mm) light green
free-floating, rootless plant. Watermeal tends to
grow in dense colonies in undisturbed water.
Often watermeal will be associated with
colonies of duckweeds. Watermeal can be an
aggressive invader of ponds and are often
found mixed in with duckweeds and other
aquatic plants. If colonies cover the surface of
the water, then oxygen depletions and fish kills
can occur. These plants should be controlled
before they cover the entire surface of the
pond1.
Distribution:
Worldwide
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(1)
Watershield - Brasenia spp.

Watershield is an aquatic floating perennial. Leaves are alternate, floating, oval to
elliptic in outline, and approximately 4 1/2 inches long and 2 1/2 inches
wide. Leaves are green and shiny on the upper surface and purple on the lower
surface. The undersides of the leaves are covered with a thick, jelly-like
substance. The leaves occur on petioles that range from 4 to 12 inches in length.
Stems are branched and may reach 6 feet in length. Primarily a weed of poorlymanaged lakes or ponds that most commonly occurs in water up to about 5 feet
deep4.
(4)
Distribution: Throughout most of
US to Southern Canada
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(4)
Water Hyacinth – Eichhoria crassipes
Distribution:
Southern US
(1)

(1)
Water Hyacinth is a free-floating perennial plant that can grow to a height of 3
feet. The dark green leave blades are circular to elliptical in shape attached to a
spongy, inflated petiole. Underneath the water is a thick, heavily branched, dark
fibrous root system. The water hyacinth has striking light blue to violet flowers
located on a terminal spike. Water hyacinth is a very aggressive invader and can
form thick mats. If these mats cover the entire surface of the pond they can
cause oxygen depletions and fish kills. Water hyacinths should be controlled so
they do not cover the entire pond1.
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White Water Lily – Nymphaea spp.
Distribution:
Throughout
North
America
(1)

The White Water Lily is a perennial plant that often forms dense colonies. The leaves
arise on flexible stalks from large thick rhizomes. The leaves are round, bright green, 6
to 12 inches in diameter with the slit about 1/3 the length of the leaf. Leaves usually
float on the water's surface. Flowers arise on separate stalks, have brilliant white
petals (25 or more per flower) with yellow centers. The flowers may float or stick above
the water and each opens in the morning and closes in the afternoon. White water lily
can spread from seeds or the rhizomes1.
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Yellow Water Lily – Nuphar spp.

(1)
Distribution:
Throughout
North America
Yellow Water Lilies are
perennial plants that arise on
flexible stalks from rhizomes
and large fleshy roots that can
resemble bananas. Leaves
are oval heart-shape, 3 to 6
inches in diameter, shiny dark
green on top and reddishpurple underneath Leaves
float on the surface and are
seldom emergent. Flowers are
large (2 1/2 to 4 inches) bright
yellow and usually stand above
the water on separate
stalks. Yellow water lilies can
reproduce from seeds or by
spreading of the rhizomes1.
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(1)
Submersed Aquatic Plants
Click on a picture to select a plant
Bladderwort
Coontail
Curly-leaf
Pondweed
Elodea
Eurasian
Watermilfoil
Richardson
Pondweed
Sago
Pondweed
Tapegrass
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Bladderwort – Utricularia vulgaris

Bladderwort is a submersed aquatic
plant that floats freely throughout
the water and have no true roots.
The bladders that occur on the
stems and leaves of all the
Utricularia species helps to
distinguish these weeds from any
other floating or submerged aquatic
weeds4.
(4)
Distribution:
Throughout
Northern
Hemisphere
(4)
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Coontail – Ceratophyllum demersum

Coontail (sometimes called hornwort)
is a dark olive-green, rootless
submerged perennial plant that often
forms dense colonies. Leaves are
relatively stiff, whorled with many
forks and small teeth along one edge.
The tips of branches are crowded with
leaves giving it a “coontail”
resemblance. Coontail reproduces by
seeds and fragmentation1.
Distribution:
Worldwide
(10)
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Curly-leaf Pondweed – Potamogeton crispus

Curly-leafed pondweed is a perennial
plant that is native to Europe and gets
it name from the rippled or wavy
nature of its submerged leaves. The
leaves are 3/4 to 4 inches long and ¼
to ½ inch wide. Mature leaves are
toothed with a distinct midrib with
paired parallel lateral veins, nearly
translucent. Fruits are seldom found.
There are small “bur” like reproductive
structures at the base of some leaves.
Curly-leafed pondweed can be an
aggressive invader that can cover
large portions of ponds1.
(4)
Distribution:
Nearly Worldwide
(10)
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Elodea - Egeria spp.

Brazilian elodea (Egeria) looks very
much like a larger, more robust version
of its commonly-found native relative,
Elodea canadensis (Canada
Waterweed)5. Egeria is native to South
America but has become naturalized in
much of the Southeastern U.S. The
dark green lance-like leaves are in
whorls of 4 to 6 which become more
dense near the tip of the stem (near the
surface). Leaves are about ½ inch wide
and from ¾ to 1 ¼ inches long with
finely toothed margins. Flowers are
white about 3/8 to ¾ inches in diameter
on short stalks which commonly are
emergent. Egeria is often confused with
the native Elodea or the non-native
Hydrilla. Hydrilla has one or more teeth
on the underside of the midrib, neither
Elodea nor Egeria have these midrib
teeth. The teeth make Hydrilla feel
rough when drawn through your hand
from base to tip1.
(1)
Distribution:
Areas of North America
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Eurasian Watermilfoil – Myriophyllum spicatum

Eurasian Watermilfoil is considered
one of the most aggressive and
problematic plants in North America
because of the dense colonies which it
forms. The stems are multi-branched,
somewhat reddish in color, with graygreenish feather-like leaves. The
leaves are in whorls of 3 to 5 around
the stem with each leaf divided into 12
or more pairs of thin thread-like
leaflets. Reddish flowers are borne on
leafless spikes that rise above the
surface a few inches. Eurasian
watermilfoil is non-native and should
not be spread1.
(2)
(1)
Distribution:
Widespread in North
America
(3)
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Richardson Pondweed – Potamogeton richardsonii
Distribution:
Widespread
throughout
North America
(10)

(10)
Richardson Pondweed has densely spaced, lance shaped leaves, 2-13 cm long, 1-3
cm wide, and have wavy often curved backwards margins. Stem often branched to 1
m long. Flowers in 4-12 whorls on short spikes. Flower stalks generally just longer
than the spike, but sometimes much longer11.
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Sago Pondweed – Potamogeton pectinatus

Sago pondweed is a perennial plant
that has no floating leaves. The stems
are thin, long and highly branching
with leaves very thin and filament-like,
about 1/16 of an inch wide and 2 to
over 12 inches long tapering to a
point. The fruit is nut-like 1/8 to 1/4
inches long and 1/10 to 1/8 inches
wide1.
(1)
Distribution:
Worldwide
(10)
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Tapegrass - Vallisneria americana

Tapegrass, Eelgrass, or Wild Celery are all
common names for Vallisneria. Tapegrass is
a rooted submerged plant often found in
flowing water. It has long, thin, ribbon-like
leaves (1/2 – ¾ inches wide) that are
commonly 3 to 4 feet long. The vein pattern
in the leaves of eelgrass is very distinctive
and resembles celery. Tapegrass has a vast
rhizome system that allows it to form dense
colonies and usually excludes other
submerged plants1.
Distribution:
Throughout
most of North
America
(10)
(1)
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Emergent Aquatic Plants
Click on a picture to select a plant
Arrowhead
Bulrush
Cattail
Fanwort
Horsetail
Pickerelweed
Purple Loosestrife
Sedges
Smartweed
Water Plantain
Water Stargrass
White Water
Buttercup
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Arrowhead – Sagittaria spp.

There are many species of
Sagittaria but all are perennial
plants that have arrowhead-shaped
leaves. Usually leaves have 3
points giving it the arrowhead
shape but some are narrow and
almost grass-like. Arrowheads can
grow in shallow water or in wet
areas. Leaves grow in clusters
from the base and can be from less
than a foot tall to over 4 feet. Leaf
petioles are long, often spongy and
have a milky-like fluid if crushed.
Rhizomes can be extensive and
some species have large tubers off
the roots. Flowers are borne on
separate stalks above the water in
whorls of three and are usually
white to light pink with three petals.
Arrowheads spread rapidly by
seeds and extensive rhizomes1.
(1)
Distribution:
Southern Canada and US
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Bulrush - Scirpus spp.
Distribution:
North
America to
Worldwide
(1)


(1)
There are several species of bulrushes. Bulrushes are perennial grass-like
plants and can grow to 10 feet tall in shallow water or in moist soils. Soft-stem
bulrush can grow to 10 feet and grows in dense colonies from rhizomes. Softstem bulrush has a round (in cross section), light gray-green, relatively soft
stem that comes to a point with no obvious leaves (only sheaths at the base of
the stems). Flowers usually occur just below the tip of the stem1.
Giant bulrush can also grow to 10 feet, is dark green with a hard, triangular
stem and no obvious leaves (sheaths at the base of the stems)1.
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Cattail - Typha spp.

Cattails have flat to slightly rounded
leaves that twist slightly over their
length and can grow to 5 or 10 feet in
height. Flowers form a dense dark
brown, cigar-shaped at the end of
spikes (called the catkin). Cattails can
be partially submerged or in boggy
areas with no permanently standing
water. Cattails spread rapidly because
their seeds blow in the wind and float
on the water's surface and vegetatively
they spread from underground
rhizomes1.
Distribution:
Worldwide
(1)
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Fanwort – Cabomba caroliniana

Fanwort is a rooted submersed plant.
It may have submersed and floating
leaves of different shapes. Fanwort
generally grows in 3-10 ft of water, and
is found in ponds, lakes and quiet
streams. Fanwort stems are long and
much-branched. Fanwort has fan-like
underwater leaves, which are about
two inches across. The submersed
leaves are frequently divided, and are
arranged oppositely or in whorls along
the stem. The floating leaves are
small, diamond-shaped, and are
infrequent. Fanwort flowers are white
to pink to purplish and are about 1/2
Distribution:
inch across. The flowers are on stalks
Mostly Eastern US
which arise from the tips of the
stems10.
(13)
(10)
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Horsetail – Equisetum hyemale

Horsetail is a perennial plant with darkgreen hollow, jointed or segmented
stems 1/4 to 1/2 inch tick with no true
leaves. Stems may be singular or
have whorls of branches. Only single
stems produce the cone-shaped spore
producing body at the tip. Horsetails
can be standing in water or in wet
areas. Horsetail stems contain silicon
crystals (i.e. sand) embedded in its
tissue. This gritty texture gives it a
common name of "scouring rush“1.
(1)
Distribution:
Northern Hemisphere
(1)
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Pickerelweed – Pontederia spp.

Pickerelweed is a perennial plant that
can grow up to 3 1/2 feet tall. Leaves
are shiny green, heart-to-lance
shaped(up to 7 inches long) singly
attached to a long petiole which grow
in a rosette from the roots. Each stem
can produce a terminal flower spike 3
to 4 inches long. The numerous
tubular flowers on the spike are violetblue in color. Each flower lasts only
one day. Pickerelweed reproduces
from seeds and rhizomes1.
Distribution:
Temperate North and
South America
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(1)
Purple Loosestrife - Lythrum salicaria

Purple loosestrife is a perennial, emergent aquatic
plant. As many as 30 -50 herbaceous, erect, annual
stems rise to about nine feet tall from a persistent
perennial tap root and spreading rootstock. The
showy, magenta flowering stems end in a 4-16 inch
flowering spike. Purple loosestrife is invasive and
competitive and unavailing to native wildlife. It can
quickly adapt to environmental changes and expand
its range to replace native plants5.
Distribution:
Throughout North
America and areas
Worldwide
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(5)
Sedges – Carex spp.

There are many types of sedges (over
100) and they are difficult to identify
without using detailed botanical
keys. In general, sedges are perennial
plants that resemble grasses, grow in
shallow water or moist soils, and can
reach 4 feet in height. Sedges often
grow in thick clusters. Stems of
sedges are usually triangular. Spikes
occur on the upper sections of the
plant and can be single or in groups1.
Distribution:
Worldwide
(1)
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Smartweed – Polygonium spp.

Smartweed is a perennial plant
that forms dense colonies in
shallow water or moist soils and
can grow to 3 feet tall. Stems are
jointed or have swollen leaf nodes
that are surrounded by a tubular
sheath. Leaves are alternate,
lance-shaped up to 4 inches long
but usually less than 1/2 inch
wide. Flowers are on spikes at the
end of stems (often numerous
spikes on the same
plant). Flowers begin as greenish
then turn whitish or a light pink in
color as they mature. Fruits are
flat, triangular (1/8 inch), dark
Distribution:
brown to black1.
Nearly Worldwide
Back to Emergent Plant Menu
(10)
Water Plantain – Alisma spp.

(11)
These perennial plants typically grow on wet soil or in
shallow water. Look for parallel veined leaves rising from
the plant base. The small white or occasionally pink
flowers occur on delicate stalks arranged in whorls
around the main flower stalk. Stiff leaves generally stand
above the water surface, but young plants often have
ribbon-like underwater leaves. What appear to be stems
are actually long leaf stalks. The stem is a bulb-like,
usually buried in sediment. White to pinkish individual
flowers to 7 mm across. They occur in whorls on slender
branches arranged around a central flower-stalk11.
Copyright property of the
Conservation Commission of the
State of Missouri
Distribution:
Nearly worldwide
Photograph by Clayton Antieau
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(11)
Water Stargrass – Heterantheria dubia

Water Stargrass is grass-like with thin
branching dark-green stems and alternate
leaves with no prominent midvein. Water
Stargrass can grow up to 6 feet long and
can form floating colonies. Flowers rise
above the surface and are bright yellow,
star-shaped, with 6 narrow petals. Water
Stargrass reproduces from seeds and
through fragmentation1.
Distribution:
Throughout
most of North
America
(1)
(1)
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White Water Buttercup – Ranunculus Aquatilis

White water buttercup is an
aquatic, perennial wildflower with
submerged stems measuring from
10-100 cm long. The leaves
alternate along the stems, the
submerge leaves dissected into
many needle-like segments. The
lower leaves are typically sessile
while the upper leaves may have
petioles measuring up to 2 cm
long. The floating leaves are similar
to the lower leaves but are 5-15
mm long and nearly twice as wide,
the blades shallowly to deeply 3lobed and with toothed or lobed
segments12.
(12)
Distribution:
Throughout most of
North America
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Other Online Aquatic Plant ID Guides

Virginia Tech Weed Guide:
www.ppws.vt.edu/scott/weed_id/aquatics.htm

University of Florida Invasive Aquatic Plant ID Guide:
http://aquat1.ifas.ufl.edu/photocat.html

Washington State Department of Ecology – Plant ID Manual Online:
www.ecy.wa.gov/programs/wq/plants/plantid2/categories.html

Texas Agricultural Extension Service – Aquaplant ID:
http://aquaplant.tamu.edu/Plant_Id.htm
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Information and Image Sources
1Texas
Cooperative Extension: http://aquaplant.tamu.edu/Floating%20Plants/Floating_Plant_Index.htm, Texas A & M University, Plant
Identification, 2004
2Non-Native
Invasive Aquatic Plants in the United States: http://aquat1.ifas.ufl.edu/seagrant/myrspi.jpg, Center for Aquatic and Invasive Plants,
University of Florida, 2001
3Simmons,
4Virginia
Kent. Eurasian Water Milfoil: http://io.uwinnipeg.ca/~simmons/ysesp/exotic4.htm, University of Winnipeg, 2004
Cooperative Extension. Aquatic Weeds: www.ppws.vt.edu/scott/weed_id/aquatics.htm, Virginia Tech, 2004
5Problem
Aquatic Plants: www.wapms.og/plants/index.html, Western Aquatic Plant Management Society , 2004
6Egmond,
Wim Van. Algae:http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/pond/, On-view.net Ltd., Microscopy
UK, 1995
7Parmentier,
Jan. Asterionella: http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/pond/, On-view.net Ltd.,
Microscopy UK, 1995
8Morgan,
Mike. Some Observations on a Freshwater Algae: http://www.microscopy-uk.org.uk/index.html?http://www.microscopyuk.org.uk/pond/, On-view.net Ltd., Microscopy UK, 2000
9MSU
Extension Bulletin. Aquatic Plant Identification and Management: http://www.pested.msu.edu/BullSlideNews/bulletins/pdf/2437/E2437_Chap5.pdf, Michigan State University, 2004
10Aquatic
and Wetland Plant and Invasive Plants: http://aquat1.ifas.ufl.edu/photocat.html, Center for Aquatic and Invasive Plants, University of
Florida, 2001-2002
11Aquatic
Plant Identification Manual for Washingtons Freshwater Plants: http://www.ecy.wa.gov/programs/wq/plants/plantid2/categories.html,
Washington State Department of Ecology * distribution info found here
12Wright,
John. Wildflowers of Ontario – White Water Buttercup: www.wildflowers.reach.net, 2001.
13Mehrhoff,
Lesli, J. Invasive Plant Atlas of New England
http://webapps.lib.uconn.edu/ipane/jpg/images.cfm?unique_identifier=uconn_ipane_cabomcarol_02, 2003
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