Plagiogyriaceae

Plagiogyriaceae Bower, Ann. Bot. 40 (1926) 484. Terrestrial ferns, small to medium sized, 10—150 cm, rarely up to 2 m high, devoid of scales. Rhizome stout, thickened, with persistent stipe bases, erect or suberect, or short decumbent, dictyostelic, sometimes bifurcate or stoloniferous; roots blackish, sparsely branched, wiry, regularly arranged on the stem, one beside each stipe base. Fronds dimorphous, bearing minute, uniseriate, multicellular, gland-headed, mucilage-secreting trichomes, of which most are lost when dry, or becoming amorphous flaky ‘scales’ at the secretion. Stipes round, oval, triangulate, or tetragonal, bearing aerophores or not; base of stipe swollen, flat on ventral face and with a strong median ridge on the dorsal face and dividing this into two surfaces, each of which bears a row of warts looking like aerophores; the stipe with a single vascular bundle which expands or divides into three meristeles in the enlarged base; rachis winged or not, ventral face sulcate, dorsal face terete, flat, or carinate, aerophores absent, or present near the base of the pinnae. Laminae of sterile fronds herbaceous to subcoriaceous, glaucous below or not, once pinnate or deeply pinnatifid; pinnae falcate to linear-lanceolate, glabrous or sparsely glandular hairy underneath, margin entire, minutely serrulate to dentate at the apex; veins simple or paired at base, mostly once to twice forked, reaching the margin of a pinna. Laminae offertile fronds similar in shape as the sterile ones, in the middle of a plant, erect, with a proportionally longer stipe and a shorter lamina, once pinnate or deeply pinnatifid, pinnae short stalked or sessile, glabrous or with few short glandular hairs at the edge, the tissue above the veinlets hygroscopic and reversible, functioning as indusium (‘false indusium’), at young stage the scarious margins covering the sori, recurved at mature stage, but when wet covering the sori again; veins free, once to twice forked, solitary or paired at the base, not entering into the scarious marginal part, margin of fertile pinnae entire or irregular, apical pinna usually pinnatifid or conform to the lateral ones, having a few lobes at base or not. Sori borne on the swollen end of veins, extended a little, confluent, ascrostichoid, nearly fully covering the lower surface of pinnae when ripe; paraphyses many, a little longer than sporangia, uniseriate, multicellular, orange to dark brown, gland-like, apically slightly capitate, deep in colour intermingled with sporangia. Sporangia with a complete oblique annulus, not interrupted by the stalk, lateral in dehiscence, 64 spores per sporangium. Spores tetrahedralglobose, trilete, the laesurae about 3/4 the radius, surface ornamentation irregular coarse tubercles, with coalescent papillae and rodlets.