Geoscience Reference
In-Depth Information
lake shorelines (Fig. 6-19). They may form dense
thickets along the margins of water bodies.
The seeds are particularly valuable for ducks;
bulrush provides nesting habitat, and it binds
wet soils quite effectively. Also known as tule
or club rush.
Cattails
(
Typha
sp.) - Among the most
common wetland plants worldwide. Long, blade-
like leaves and stiff l ower stalks. The mature seed
head looks like a brown sausage (Fig. 6-20).
Two varieties are common in North America:
common cattail (
T. latifolia
), up to 2.5 m tall,
and narrow-leafed cattail (
T. angustfolia
), up to
1.5 m tall, as well as a hybrid (
Typha x glauca
).
Normally found in shallow water of pond
margins and marshes, but may thrive in almost
any saturated soils from roadside ditches to
sinkholes. Cattail is commonly used for wetland
reconstruction and water treatment in artii cial
wetlands (Anderson 2006).
Pickerel weed
(
Pontederia cordata
) - A per-
ennial plant that reaches four feet (1.2 m) in
height and grows in dense colonies along shallow
shorelines (Fig. 6-21). It tolerates low nutrients
and temporary l ooding. Its natural range is from
Nova Scotia to Texas in eastern North America,
and it is widely used in water gardens because
of its showy violet l owers. Seeds are eaten by
waterfowl; geese and muskrats eat the vegeta-
tion; i sh and some birds and mammals use
pickerel weed for cover (Miller 2002).
A
B
6.2.3 Floating plants
This category includes plants whose leaves
mainly l oat on the water surface. Much of the
plant body is underwater. Some are rooted in
the substrate, generally
2 m deep, and others
are completely free l oating near the surface in
water of any depth. Only small portions, namely
l owers, rise above water level. Again, this cat-
egory is easily recognized by most people as
hydrophytes.
Duckweeds
(family Lemnaceae) - Numerous
genera and species make up this family, which
comprises the smallest and simplest of all l ow-
ering plants (Fig. 6-22). They are also among the
most common plants worldwide. The plant con-
sists of a photosynthetic l oating body, called a
<
Figure 6-18.
Midwestern arrowhead (
Sagittaria
brevirostra
). A. Arrowheads form a dense carpet on a
pool at Squaw Creek National Wildlife Refuge, Missouri
River bottomland, northwestern Missouri, United States.
B. Close-up view of a single arrowhead leaf, about one
foot (30 cm) tall. Kahola Creek, Kansas, United States.
Photos by J.S. Aber.
