大叶黑桫椤 da ye hei suo luo

Alsophila gigantea var. polynervata (R. H. Miao) Q. Xia; A. helferiana C. Presl; A. henryi Baker; A. polycampta Kunze; A. umbrosa Wallich ex Ridley; Cyathea gigantea (Wallich ex Hooker) Holttum; C. gigantea var. polynervata R. H. Miao; C. henryi (Baker) Copeland; C. pectinata Ching & S. H. Wu; C. petiolulata Ching & S. H. Wu; C. pseudogigantea Ching & S. H. Wu; C. tinganensis Ching & S. H. Wu; Gymnosphaera gigantea (Wallich ex Hooker) J. Smith; G. gigantea var. polynervata (R. H. Miao) Y. K. Yang & J. K. Wu.

Trunk erect, 2-5(-7) m tall, up to 20 cm in diam. Fronds 2-pinnate-pinnatifid, 2-3 m; stipe black, ca. 1 m or more, scabrous, sparsely hairy, base and adaxial side with dense dark brown scales; scales dark brown, lustrous, ca. 2 cm × 1.5-3 mm at base, with a narrow paler margin and fragile edges, spreading; rachis dark or black, rough after abscission of scales; pinnae spreading, shortly stipitate, oblong, 50-60 × ca. 20 cm at middle; abaxial side of costae subglabrous, adaxial side with sparse dark hairs; pinnules ca. 25 pairs, lanceolate, ca. 10 × 1.5-2 cm, pinnatifid 1/2-3/4 to costule, alternate, spreading, with short stipe ca. 2 mm; abaxial side of costule with small scales, adaxial side hairy; pinnule segments 12-15 pairs, slightly ascending, broadly triangular, 5-6 × 4-5 mm, margin minutely serrulate, apex obtuse; veinlets 6 or 7 pairs, simple, basal basiscopic veinlets arising from costule. Lamina papery, abaxially gray-brown, adaxially dark brown, both surfaces glabrous. Sori orbicular, medial, forming V-pattern; paraphyses as long as sporangia; indusia absent.

Beside valley streams in dense forests; 200-1200 m. Guangdong, Guangxi, Hainan, Yunnan [Cambodia, India, Indonesia (Java), Laos, Myanmar, Nepal, Sri Lanka, Thailand, Vietnam].