20. Pyrrosia boothii (Hooker) Ching, Bull. Chin. Bot. Soc. 1: 66. 1935.
冯氏石韦 feng shi shi wei
Polypodium boothii Hooker, Sp. Fil. 5: 53. 1863; Cyclophorus boothii (Hooker) C. Christensen; C. subvelutinus (Christ) C. Christensen; Niphobolus boothii (Hooker) Beddome; N. subvelutina Christ; Pyrrosia fengiana Ching; P. subvelutina (Christ) Ching.
Plants 30-70 cm tall. Rhizome short or occasionally shortly elongated, to ca. 8 mm thick, in cross section with many scattered sclerenchyma strands; phyllopodia close, lateral buds situated basal on phyllopodia. Scales pseudopeltate, to 11 × 1.5 mm, base entire to ciliate; acumen brown, dentate to shortly ciliate. Fronds monomorphic, stipitate; stipes 15-30 cm, 0.5-1 × as long as lamina; lamina widest at middle, 20-36 × 4.5-8 cm, base cuneate and slightly decurrent, apex ± acuminate. Hydathodes distinct, superficial or sunken. Indument dimorphic, brown; upper layer not very dense, hairs to 2 mm in diam., with acicular rays, lower layer densely covering lamina, with mainly woolly rays. Sori superficial, without central bundle of paraphyses. Sporangia with stalks 0.5-0.75 × as long as capsule.
On rocks in forests; 1600-2100 m. Xizang, Yunnan [Bhutan, India].
Pyrrosia boothii can be distinguished from P. drakeana by the longer rhizome scales, which are dentate, at most shortly ciliate, the shorter stipe, and often the longer fronds, with equal, cuneate base.