Family Description: Rhizome solenostelic or rarely dictyostelic, with opaque scales. Petiole usually dark and shining, with 1 or 2 vascular strands at the base which divide distally. Sori usually submarginal and often borne on or covered by the deflexed leaf-margin which forms a pseudoindusium; spores tetrahedral or globose
Family Description: Rhizome dictyostelic, with clathrate scales. Petiole with 2 vascular strands, often fusing to form a single ×-shaped strand. Sori superficial, borne along one or both sides of the fertile veins; spores bilateral.
Family Description: Rhizomes subterranean, far-creeping. Stems grooved and regularly jointed. Leaves in whorls, united at the base into a sheath. Homosporous; cones composed of sporangiophores; sporangia borne beneath the peltate heads of the sporangiophores; spores spherical with 4 elaters, green. Prothallus green.
Family Description: Free living primitive plants which reproduce by means of spores instead of flowers and seeds. Mostly all perennial due to underground stock; usually solenostelic rhizomes with opaque scales. Spore producing organs (=Sporophytes) have vascular tissue and are borne under the leaves. Fertile and sterile leaves are somehow different. The tiny (powder-like) spores produced by the sporangia give rise to filamentous or thalloid gametophytes called prothalli which develop to form new plants. Plants have petioles with 2 vascular strands. The sporangia are arranged in a series of rows along the veins and not in well-defined sori. Soral induism absent. Spores tetrahedral shape.
Family Description: Stem short, 2- or 3-lobed. Leaves in a rosette; leaf-base spathulate, with a membranous margin, with a delicate ligule on the adaxial surface at the point where the leaf narrows. Heterosporous; megaspores tetrahedral; microspores bilateral, in separate sporangia.
Family Description: Rhizome polystelic or solenostelic, with opaque scales. Leaves 2-ranked on the upper side of the rhizome and articulated to it; petiole with 1-3 major vascular strands. Sori superficial, without indusium; spores bilateral.
PTERIDACEAE ( Fern Family )
Family Description: Rhizome solenostelic or dictyostelic, with opaque scales. Petiole with a single U-shaped strand. Sori submarginal, forming coenosori which are borne on the veinlet connecting the vein ends, and which are covered by the scarious, deflexed leaf-margins; spores tetrahedral, opaque.
Family Description: Stems erect or creeping. Leaves numerous, simple, small, 1-veined, with a ligule on the adaxial surface. Heterosporous; sporangia grouped in strobili; individual sporangia solitary at the base of the sporophylls, unilocular; spores tetrahedral.