| Author | L. | |
| Distribution | Mostly outer Coastal Plain, but extending sporadically inland to Forsyth and Rowan counties. A specimen from Orange County came from a UNC professor's garden.
Newf. to AK, south to FL, TX, and CA; W.I., Mex., C.A., S.A. | |
| Abundance | Uncommon in the Coastal Plain, but more populations will likely be found with directed searches. Extremely rare in the Piedmont. | |
| Habitat | Impoundments, ponds, woodland pools, slow-moving streams and rivers, fresh-tidal to brackish waters of sounds, interdune ponds. |
| Phenology | Flowering and fruiting May-September. | |
| Identification | Common Hornwort can best be told from our other two species by its leaves, which are only 1-2 times forked (vs. 3-4 times). Though hardly common, it is by far the most numerous of the 3 hornwort species in the state. | |
| 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) | Coontail, Rigid Hornwort | |
| State Rank | S3? | |
| Global Rank | G5 | |
| State Status | | |
| US Status | | |
| USACE-agcp | OBL link |
| USACE-emp | OBL link |
