1. lower vascular plants having dichotomously branched sporophyte divided into aerial shoot and rhizome and lacking true roots; [syn: Psilotales, order Psilotales]
WordNet (r) 3.0 (2006):
order Psilotales
n 1: lower vascular plants having dichotomously branched
sporophyte divided into aerial shoot and rhizome and
lacking true roots [syn: Psilotales, order Psilotales]