拟大羽铁角蕨 ni da yu tie jiao jue

Plants up to 1 m tall or more. Rhizome erect, apex scaly; scales dark brown, narrowly triangular, entire. Fronds caespitose; stipe dull to semi-shiny, purplish black to brown-gray, 20-45 cm, adaxially sulcate, base with brown narrowly triangular scales, glabrous toward rachis; lamina triangular to ovate-elliptic, 40-70 × 15-30 cm, apex acute, 3-pinnate to 4-pinnatifid; pinnae up to 16 pairs, basal pinnae not reduced and subopposite, upper ones alternate, with stalk up to 1.5 cm, triangular to narrowly triangular, 7-15 × 4-11 cm, base broadly cuneate, bipinnate to tripinnatifid, apex acute; pinnules 10-14 pairs, anadromous, stalks 5-7 mm, less than twice as long as wide, basal acroscopic and basiscopic pinnules ± equal, basal pair largest, triangular to rhombic, 2-7 × 1.5-4 cm, base obliquely truncate, pinnate to 2-pinnatifid, apex acute; ultimate pinnules 2-6 pairs, anadromous, basal segment pair on basal pinnules subequal, largest, rhombic to cuneate, 1.5-2 × 1.5-1.7 cm, base broadly cuneate to cuneate, shortly stalked, 2- or 3-partite or simple, apex obtuse; segment rhombic to cuneate, lateral sides entire, apex bicrenate, apex obtuse to truncate. Veins distinctly raised adaxially, venation anadromous, veins almost reaching margin, pseudovein in first acroscopic sinus of basal pinnules. Fronds soft papery, brown-green when dry, subglabrous; rachis and costa dull purplish black to gray-brown, semiterete, adaxially sulcate; costule green. Sori linear, 4-6 mm; indusia membranous, entire, opening toward main vein of segment, persistent.

On rocks at streamsides in forests; 800-900 m. Guangdong, Guangxi, Taiwan, Yunnan [Vietnam].