Description:
A rooted perennial aquatic herb with a long, robust stem, usually
deep red or brownish red in color. Leaves may exhibit two distinctly
different forms.
Submerged Leaves fine and numerously dissected, in whorls of 4-6
or some scattered, ½"-2½" long, with 6-12
pairs of segments, yielding a delicate, feather-like or "coontail" appearance.
This portion of the plant is usually a reddish or greenish brown
in color. Emergent Leaves small, bright green, and oval in shape,
with or without teeth along the edges, up to ¼" wide,
borne in whorls on a stalk-like portion of the stem, rising 6"-8" above
the water. So different from the submerged leaves they are often
mistaken as being another plant altogether. Emergent growth is generally
associated with mature stages and may not be evident until late summer.
Stem
stout, simple or branching, 3mm-8mm in diameter, often tinged in
red; to 3' or longer. Rather stout, smooth, branched. Winter buds
produced at the plant base or from rhizome
Roots
white, unbranched, and thread-like. Not always present.
Flowers
in green to reddish spikes raised above the water's surface, 2"-12" long; the male usually in the upper part of the
spike, the female in the lower. Floral bracts whorled, smaller than
foliage leaves, ovate, sharply toothed, spreading, or curved downward;
up to 1/24" long. Flowers both perfect and imperfect; petals
of male and perfect flowers 1mm-3mm long.
Fruit olive, more or less round, 2mm long; fruit segments rounded
or with 2 small ridges or keels on the dorsal side, otherwise smooth.
Conspicuously beaked with the recurved stigma.
- Mechanical: Benthic
barriers or other bottom-covering approaches are another physical
management technique that has been in use for a substantial
period of time. The basic idea is that the plants are covered
over with a layer of a growth-inhibiting substance.
- Biological: Not
known
- Herbicide:
Not Known
For More Information:
Detailed information about noxious weeds is available at the Washington
State Noxious Weed Control Board Web Site. |
