Psilotatae is a term used to refer to the family of whisk ferns, which are ancient plants that have no true roots or leaves. Some synonyms for Psilotatae include "Psilotophyta," "Psilopsida," and "Psilophyta." These terms refer to the same group of plants and are often used interchangeably. Other synonyms that may be used include "rhyniophytes," "lycopsids," and "clubmosses." These plants are of great scientific interest as they represent an important part of the evolutionary history of land plants. They are found in a variety of habitats, from moist rainforests to arid deserts, and their unique morphology provides insight into the adaptations and mechanisms that allowed plants to thrive on land.