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Noun1.Psilotales - lower vascular plants having dichotomously branched sporophyte divided into aerial shoot and rhizome and lacking true roots
plant order - the order of plants
class Psilopsida, class Psilotatae, Psilopsida, Psilotatae - whisk ferns; comprising the family Psilotaceae or Psilotatae: vascular plants with no roots, partial if any leaf differentiation, and rudimentary spore sacs
family Psilotaceae, Psilotaceae - small family of lower ferns having nearly naked stems and minute scalelike leaves
References in periodicals archive ?
Hints of an earlier stage of 'isomorphic' alternation in vascular plant life-cycles can be found in studies of the lesser-known gametophytes of modern Lycopodiales, Psilotales, and Ophioglossales.
The Psilotales and Ophioglossales also possess subterranean, non-photosynthetic gametophytes, whereas Equisetum and most ferns (Stromatopteris is an exception) have photosynthetic gametophytes.