Plagiogyria euphlebia (Kunze) Mett.

Rhizome short, erect to decumbent, narrow, sometimes very woody. Stipes stramineous to brownish, of sterile fronds (7-)25-35(-70) cm long, of fertile fronds (9-)40-77 cm long, base slightly to strongly enlarged, 5-10(-20) mm wide in the middle, in cross section one V-shaped to one U-shaped vascular bundle, upper part of stipe terete or oval (usually) or tetragonal, aerophores only present on base of stipe or seemingly absent at dry stage, present on base of stipe and lower part of rachis, or present on stipe and rachis, cushion-like; rachises glabrous to hairy to sometimes densely hairy. Fronds not covered with an amorphous gelatinous mucilage layer when dry, dorsal side of rachis semiterete (usually), flattened or grooved, not winged, rachis 1-2(-5) mm wide in the middle part. Sterile lamina herbaceous to firm herbaceous to subcoriaceous (very rare, found near the sea), not glaucous, pinnate, apical pinna base free, or sometimes connected with upper lateral ones, or rarely pinnate except the pinnatifid or pinnatilobed apex, widest basally to medially, (11-)20-60(-136) by (7-)12-30(-40) cm, index 1.36-2.5(-3.8); pinnae 7-25 pairs, widest medially, veins of pinnae simple to as many as forked, distinct on both surfaces, stomata scattered on the lower epidermis, margin serrulate or towards the base becoming entire or nearly so, most pinnae except the uppermost with equilateral, cuneate, rounded, or attenuate base; lowermost pinnae shortly stalked or rarely sessile, not deflexed, not or slightly shortened (the basal pair); middle pinnae (5-)11-17(-30) cm long, 0.9-2(-2.6) cm wide in the middle, shortly stalked or sessile, base cuneate or rounded; apex of lamina terminated by a pinna conform to lateral ones or rarely pinnatifid, base with 1-3 irregular auricles or free, shortly stalked, or connected with 1 or 2 shorter lateral pinnae (sometimes connected with more than 2 pairs), (4-)7-10(-30) cm long, terminated by a pinnatilobed, short-triangular or pinna-like segment. Fertile fronds usually longer than the sterile ones, rarely shorter or about the same length, dorsal side of rachis semiterete (usually), flattened, or grooved, not winged, rachis 1-2(-5) mm wide in the middle part; lamina pinnate throughout, pinnae shortly stalked or nearly sessile, (9-)20-50(-80) cm long, (3-)10-20(-33) cm wide; pinnae glabrous or sparsely bearing short glandular hairs, 7-25 pairs, margin entire, subentire, or erose; lowermost pinnae not shortened (or the basal pair shorter), (1-)4-6(-8) cm apart; middle pinnae (2-)7-20(-33) cm long, 2-4(-5) mm wide, base shortly stalked to sessile; apex terminated by a pinna conform to the lateral ones and often beaded at the base. Paraphyses many, brown. Spores yellow or brown, with reddish tubercles.