2. Araiostegia hookeri (T. Moore ex Beddome) Ching in S. S. Chien & Chun, Fl. Reipubl. Popularis Sin. 2: 291. 1959.
宿枝小膜盖蕨 su zhi xiao mo gai jue
Acrophorus hookeri T. Moore ex Beddome, Ferns Brit. India 1: 95. 1865; Araiostegia clarkei (Baker) Copeland; A. parva Copeland; Araiostegiella clarkei (Baker) M. Kato & Tsutsumi; A. hookeri (T. Moore ex Beddome) Fraser-Jenkins; Davallia clarkei Baker; D. hookeri (T. Moore ex Beddome) X. C. Zhang; D. subalpina Hayata; Humata hookeri (T. Moore ex Beddome) Diels; Leucostegia clarkei (Baker) C. Christensen; L. hookeri (T. Moore ex Beddome) Beddome; L. parva (Copeland) C. Christensen.
Rhizome 3-4 mm in diam., densely covered with scales, not white waxy. Scales brown, without pale border, narrowed evenly toward apex, basifixed with cordate base and much overlapping lobes, 6-7 mm, without multiseptate hairs, lacking marginal setae or teeth, or those rare, or toothed. Stipe pale, adaxially grooved, 7-15 cm, covered with scales near base, sparsely scaly above base; lamina thinly papery, yellowish green when dry, tripinnate, deltoid and broadest toward base, 15-20 × 6-10 cm, glabrous, not or slightly dimorphic. Petiolules ± lacking, generally lowest pinnule inserted at very base of pinna rachis; pinnae deltoid or linear-triangular, 3-6 × 1-2 cm; basal pinnae opposite, alternate distally, sessile, basal pair similar to distal one, elliptic-lanceolate; pinnules 8-10 pairs, subsessile, obliquely ovate, 6-10 × 3-5 mm; ultimate pinnae linear-oblong, lobed almost to midrib; ultimate segments or lobes obtuse or acute without a tooth, narrowly linear, ca. 0.5 mm wide. Rachises and costae glabrous. Rachis with an ovate scale at forking point. Veins in sterile ultimate lobes frequently simple, not reaching margin; false veins not present. Sori separate, frequently single on a segment, terminal on veinlet; indusium semicircular, attached at base, wider than long or ± as wide as long.
Dense mixed forests, epiphytic on tree trunks, also on rocks; 1200-4000 m. Sichuan, Xizang, Yunnan [Bhutan, India, Nepal].
One of us (Nooteboom) considers both Araiostegia faberiana and A. perdurans to be conspecific with A. hookeri, having seen 113 specimens with duplicates from A, BM, IBSC, K, KUN, KYO, L, P, PE, SING, TI, and UC, as well as the types of Davallia clarkei var. faberiana and D. perdurans, neither of which is different from A. hookeri. However, two of us (Xing and Wang) do not agree and consider that A. hookeri differs from A. faberiana and A. perdurans in having lamina tripinnatifid, pinnae articulate to the rachis, and stipes and rachis persistent and turning black when pinnae fall according to field observations and herbarium specimens.