Austrocylindropuntia and Ceratopteris are both examples of what taxonomic category?
Austrocylindropuntia: Austrocylindropuntia is a genus of cacti (family Cactaceae) with 11 recognized species, which were once included in the genus "Opuntia". Ceratopteris: Ceratopteris is the only genus among homosporous ferns that is exclusively aquatic.
genus