Assertion: rigid hornwort | /r/HasProperty | ceratophyllum demersum
Facets:
Source sentences:
text: The genus Ceratophyllum is sufficiently unique in the plant kingdom to justify its own family, the Cetatophyllacaea, in which most people recognise two species, soft hornwort (Ceratophyllum submersum) and rigid hornwort (Ceratophyllum demersum) although there is variability that has prompted some researchers to propose division into more species.
text: Rigid hornwort (Ceratophyllum demersum) grows in similar situations and is superficially very similar to soft hornwort.