壮乡铁角蕨 zhuang xiang tie jiao jue

Plants 5-15 cm tall. Rhizome erect, apex scaly; scales dark brown to black, narrowly triangular to subulate, margin fimbriate to subentire. Fronds caespitose; stipe shiny castaneous to purplish black, 0.7-4 cm, semiterete, threadlike, with brown, multicellular uniseriate hairs or subglabrous; lamina oblong-ovate, 3-12 × 1-3.5 cm, 3-pinnate, apex acute; pinnae 8-17 pairs, subopposite to alternate, overlapping, shortly stalked, median pinnae largest, ovate, 0.5-2 × 0.4-1.5 cm, base truncate, 2-pinnate, apex obtuse; pinnules 2-4 pairs, anadromous, basal acroscopic pinnule largest, triangular-ovate, stalked, apex obtuse, pinnate; ultimate segments bifid or simple (sterile) and linear-subulate, 1-2.5 × 0.2-0.5 mm, apex acute; fertile segments wider than sterile. Costa and costules sulcate adaxially, green, veins anadromous, 1 vein per segment, terminal hydathode not reaching margin. Fronds thinly herbaceous, green, lamina with multicellular uniseriate hairs or subglabrous; rachis shiny castaneous to purplish black, becoming green in upper half toward apex, sulcate adaxially, with brown, multicellular uniseriate hairs or subglabrous. Sori 1 per fertile segment, basal on acroscopic veinlet, often spreading and hidden by indusium at maturity, oval, 0.5-0.9 mm; indusium semi-elliptic, hyaline, entire to repand, opening toward costules and margin, persistent. Spores brown, with lophate (cristate-alate) perispore.

● In crevices of karst caves; 700-800 m. Guangxi.