| Noun | 1. | family Psilotaceae - small family of lower ferns having nearly naked stems and minute scalelike leaves fern family - families of ferns and fern allies order Psilotales, Psilotales - lower vascular plants having dichotomously branched sporophyte divided into aerial shoot and rhizome and lacking true roots genus Psilotum, Psilotum - type genus of the Psilotaceae |