any aquatic plant of the genus Ceratophyllum, forming submerged branching masses in ponds and slow-flowing streams: family Ceratophyllaceae
2.
any of a group of bryophytes belonging to the phylum Anthocerophyta, resembling liverworts but with hornlike sporophytes
hornwort in American English
(ˈhɔrnˌwɜrt)
noun
1.
any of a genus (Ceratophyllum) of long, rootless waterlilies of the hornwort family submerged in lakes and slow-moving streams and having whorls of finely divided leaves
adjective
2.
designating a family (Ceratophyllaceae) of dicotyledonous, rapidly growing waterlilies