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Psilotophyta (the so-called "whisk ferns"; also sometimes as Psilophyta) is a division (i.e., phylum) of the Kingdom Plantae. This division contains only two genera: Psilotum, a small shrubby plant of the dry tropics, and Tmesipteris, an epiphyte found in Australia, New Zealand, and New Caledonia. There has long been controversy about the relationships of the Psilotophyta, with some claiming that they are ferns (Pteridophyta), and others maintaining that they are descendants of the first vascular plants. Recent evidence from DNA suggests a closer affinity to the ferns.
All Psilotophyta share a few characteristics. Psilotophyta are all vascular plants. They lack leaves, instead having small outgrowths called enations. The enations are not considered true leaves because there is only a vascular bundle just underneath them, but not inside, as in leaves. Psilotophyta also don't have true roots. They are anchored by rhizoid s. Absorption is aided by fungi called mycorrhizae.
Three sporangiaA sporangium (pl. sporangia is a plant structure producing and containing spores or gametes. Sporangia occur on angiosperms, gymnosperms, ferns, fern allies, mosses, algae, and fungi. Microsporangia are the structures on the stamens of flowers called anth are united into a synangium, which is considered to be a very reduced series of branches. There is a thick tapetum to nourish the developing sporeThe term spore has several different meanings in biology. Spores are: diaspores (dispersal units) of fungi, mosses, ferns, fern allies, and a few other plants; The gametes of the higher vascular plants ( angiosperms and gymnosperms)—the microspores ( polls, as is typical of eusporangiate plants. The gametophyteA gametophyte is the haploid structure or phase of life of a sexually reproducing plant. Each cell of a gametophyte contains one complete set of chromosomes. The gametophyte can be the dominant part of the plant's life cycle as in mosses, or very reduced looks like a small piece of subterranean stem, but produces antheridiaAntheridium (plural: antheridia is a structure or organ of the gametophyte phase of certain plants producing and containing the sperm or male gametes. It is present in lower plants like mosses and ferns, but the comparable structure in gymnosperms ( micro and archegoniaAn archegonium (plural: archegonia is a multicellular structure or organ of the gametophyte phase of certain plants producing and containing the ovum or female gamete. Archegonia are typically located on the surface of the plant thallus, although they are.
