Publication: Ann. Lyceum Nat. Hist. New York. 4: 49. 1837.
selected vouchers: WTU
Notes: FNA3: "Principally an eastern North American species--and the only species of its genus endemic to North America-- Ceratophyllum echinatum is disjunct in the Pacific Northwest as a result of repeated Pleistocene glaciation. The habitats of C . echinatum are typically more acidic (avg. pH 6.6) than those of C . demersum (avg. pH 7.4). The two species only rarely coexist. Ceratophyllum echinatum also thrives in cooler, clearer, and more oligotrophic water than C . demersum and often is found in more ephemeral sites, such as shrub swamps (e.g., with Cephalanthus occidentalis ) and beaver ponds.
This species, relatively uncommon, is fast disappearing from much of its range because of habitat alteration or destruction and the introduction of nonindigenous species; steps should be taken to secure its conservation. Unlike Ceratophyllum demersum , C . echinatum does not attain status as a serious weed."