苏铁蕨 su tie jue

Bowringia insignis Hooker, Hooker’s J. Bot. Kew Gard. Misc. 5: 237. 1853; Brainea formosana Hayata; B. insignis var. formosana (Hayata) Tagawa.

Stem blackish brown, erect, stout, up to ca. 1 m tall, 10-15 cm in diam., woody, apex scaly; scales rufous, linear, up to 3 cm, membranous, acuminate. Fronds clustered in terminal crown, slightly dimorphic; stipe brownish stramineous, 10-30 cm, basal part scaly; lamina pinnate, elliptic-lanceolate, 50-100 cm, slightly narrowed downward, leathery, abaxially with some small scales along costa and veins; pinnae 30-55 pairs, opposite or alternate, subsessile, linear to narrowly oblong; middle pinnae 10-15 × 0.7-1.2 cm, base asymmetrical, subauriculate, margin serrulate; basal pinnae slightly shortened; veins free, simple or 1- or 2-forked, except for costal row of areoles subtriangular; fertile pinnae somewhat shorter, margin sometimes irregularly lobed; rachis stramineous, grooved adaxially. Sori borne on costal veins, exindusiate, abundant, covering whole abaxial surface of pinnae when mature. 2n = 66.

Damp and exposed hillsides; 300-1700 m. Fujian, Guangdong, Guangxi, Guizhou (Anlong, Zhenning), Hainan, C Taiwan, Yunnan [tropical regions of Asia].