Coontail, Hornwort
Ceratophyllym demersum
Native to Chesapeake Bay
- Family - Ceratophyllaceae
- Distribution - Coontail usually grows in freshwater
reaches of tributaries with moderate to high nutrient concentrations and can be
found to depths of 2 meters. It is also found in some lower salinity tidal areas
(e.g., the Middle River, the Potomac River near Alexandria, and Lake Placid on
the Magothy River). It is fragile and limited to slow moving water in streams
and ponds. It can also be found in the interior of large beds comprised of other
bay grass species. Unlike other bay grass, coontail has no true roots and is free-floating,
and therefore does not require any particular substrate, but instead absorbs
nutrients from the water column.
- Recognition - Coontail, because it has no true roots,
may float in dense mats beneath the water surface and is only occasionally
attached to the sediment by its basal ends. Coontail has slender, densely
branched stems of up to 2.5 m (9 ft) in length. The compound leaves of coontail
are divided or forked into linear and flattened segments 1 cm to 3.5 cm (2/5 in
to 1 3/5 in) long with fine teeth on one side of the leaf margin. Leaves have a
stiff and brittle texture and grow in whorls of 9 to 10 at each stem node with
whorls becoming more crowded towards the stem tips.
- Ecological Significance - Coontail is found in all 50 states
and Puerto Rico. Unlike the other bay grass found in the Chesapeake Bay, coontail has
no true roots and obtains all its nutrients directly from the water column. It
is very shade tolerant and can form large, dense mats in tidal freshwater
tributaries of the bay and in slow-moving streams and ponds.
- Similar Species - Eurasian watermilfoil
(Myriophyllum spicatum) has roots and pinnate leaves and is very
different in form from coontail, appearing more feathery and limp when held out
of the water.
- Reproduction - Coontail reproduces asexually (vegetatively) and
sexually (by seed). Stem fragments with lateral buds develop into new plants
throughout the season. In autumn stem tips break off and over-winter on the
bottom before sprouting in spring. Occasional sexual reproduction produces small
purple flower clusters between July and September, followed by a single nut-like
seed. Shade-tolerance and its floating habit make turbidity less of a limiting
factor for coontail than for other bay grasses.
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