whisk ferns; comprising the family Psilotaceae or Psilotatae: vascular plants with no roots, partial if any leaf differentiation, and rudimentary spore sacs
双语例句
In most modern classifications they are placed in the class Psilopsida of the Filicinophyta. 在大多数现代分类系统中，它们被分为真蕨植物门裸蕨植物亚门裸蕨纲。
