显脉瘤蕨 xian mai liu jue

Polypodium membranifolium R. Brown, Prodr. 147. 1810; Microsorum membranifolium (R. Brown) Ching; M. nigrescens (Blume) Copeland; Phymatodes nigrescens (Blume) J. Smith; P. nigrescens var. variabilis (Ching) C. Christensen & Tardieu; P. variabilis Ching; Phymatosorus nigrescens (Blume) Pichi Sermolli; P. variabilis (Ching) Pichi Sermolli; Pleopeltis nigrescens (Blume) Carruthers; Polypodium nigrescens Blume.

Rhizome 10-15 mm in diam., scaly; scales brown, orbicular or oblong, peltate, thin, margin irregularly toothed, apex rounded. Stipe straw-colored, 30-40(-50) cm, ca. 5 mm in diam., glabrous. Lamina usually pinnatifid, rarely pinnately ternate, dark green, 50-80 × 30-40 cm, or simple, 15-25 × 4-5 cm; lateral lobes usually (2 or)3-10(-12) pairs, ascending, broadly lanceolate, 15-20 × 3-4 cm, papery, both surfaces glabrous, base somewhat narrowed, margin subentire, apex caudate-acuminate; veins all distinct, areoles with forked included veinlets. Sori orbicular, ca. 4 mm in diam., in 1 row on each side of midrib, medial, abaxially distinctly hollow and adaxially distinctly raised.

Terrestrial or on rocks in tropical rain forests; 200-1200 m. Hainan, Taiwan, Yunnan [Cambodia, India, Indonesia, Malaysia, Philippines, Sri Lanka, Thailand, Vietnam; Pacific islands (Polynesia)].

Beddome (Ferns S. India, t. 176. 1864) named material of Phymatosorus membranifolius as Pleopeltis longissima (Blume) T. Moore.