Details
Herbaceous, terrestrial or sometimes epiphytic fern-allies. Rhizome micorrhizal, without roots, with rhizoids, which is called a rhizomatous perennial, mycorrhizal, herb or lower vascular group. Vascular system protostelic. No true fronds found in this group. Aerial stem or stipe erect or pendulus, repeatedly dichotomously branched above, branched angled or flat. Fronds or leaves scale-like, very small, non-photosynthetic, devoid of stomata and vascular tissue, trifarious or distichous with out midrib. Sporangium a synangium type, united in three lobes, borne at the base on the upper surface of 2-3 lobed sporophylls, eusporngiate. Spores numerous, homosporous, minute, monolete. Gametophytes cylindrical, subterranean, mycorrhizal.