Author | A. Gray | |
Distribution | Scattered records on the Coastal Plain; also Richmond County in an old oxbow of the Pee Dee River (in the eastern Piedmont), and a second Richmond population in a pond at Pee Dee NWR.
Newf. to Ont. and MN, south to central FL and eastern TX; also BC, WA, OR. | |
Abundance | Rare to locally uncommon. Where found, plants may be numerous. Presumed to occur in many more counties than collected so far. It is a Watch List species, as assigned by NCNHP. | |
Habitat | Impoundments, woodland and forest pools (such as cypress-gum), slow-moving streams and rivers. |
Phenology | Flowering and fruiting May-September. | |
Identification | Spineless Hornwort has leaves which fork 3-4 times (vs. 1-2 in C. demersum) and lax and slender leaves (vs. stiff and coarse in that species). From C. australe, it differs in larger seeds (4.5-6 mm vs. 3-4.5 mm). | |
Taxonomic Comments | Hornworts/Coontails (genus Ceratophyllum) are submersed aquatic plants with long stems and branches. Leaves are very slender, linear, forked, and are arranged in whorls of 3-11 leaves. Tiny flowers and fruits occur at some leaf bases. Plants superficially resemble water-milfoils, but leaves of milfoils are pinnately dissected into many segments, not merely forked. | |
Other Common Name(s) | Prickly Hornwort, Spiny Coontail | |
State Rank | S2 | |
Global Rank | G4 | |
State Status | W7 | |
US Status | | |
USACE-agcp | OBL link |
USACE-emp | OBL link |