西亚桫椤 xi ya suo luo

Alsophila pingbianica Y. K. Yang, Y. M. He & J. K. Wu; Cyathea khasyana (T. Moore ex Kuhn) Domin; Gymnosphaera hongheensis Y. K. Yang, Z. Y. Yu & J. K. Wu; G. khasyana (T. Moore ex Kuhn) Ching; G. pingbianica (Y. K. Yang, Y. M. He & J. K. Wu) Y. K. Yang & J. K. Wu.

Trunk erect, ca. 1.5 m or more. Fronds 2-pinnate-pinnatifid, 2-3 m; stipe dark, up to 40 cm or more, glabrous, not spiny, densely scaly at base; scales abundant, dark, ca. 1.5 cm × 1.5 mm, with broad, pale, ciliate margins; lamina up to 70 cm or more; pinnules alternate, spreading, lanceolate, 8.5-10 × 1.5-2.5 cm, base truncate, shortly stalked, deeply pinnatifid, apex acuminate; pinnule segments ca. 17 pairs, alternate, spreading, approximate, oblong, ca. 8 × 4 mm, dentate at apex and margin, basal pair almost free, upper part pinnatifid almost to costule; veinlets 8 or 9 pairs, simple or forked, basal basiscopic ones arising directly from pinnule costule. Lamina thin, dark brown on adaxial surface, pale green on abaxial surface; rachis and costae dark brown, glabrous on abaxial side, adaxial side with dense reddish brown stiff hairs; adaxial side of costules with small dark brown, lanceolate scales; adaxial side of midveins with sparse, small, brown bullate scales. Sori close to midveins, often 4 pairs; indusia absent.

Forests; 1200-1800 m. Xizang, Yunnan [India, Myanmar].