Noun | 1. | ![]() fern family - families of ferns and fern allies Marattiales, order Marattiales - lower ferns coextensive with the family Marattiaceae genus Marattia, Marattia - type genus of the Marattiaceae: ferns having the sporangia fused together in two rows genus Angiopteris - one species: tree fern Danaea, genus Danaea - fairly small terrestrial ferns of tropical America |