2. Polypodiastrum argutum (Wallich ex Hooker) Ching, Acta Phytotax. Sin. 16(4): 28. 1978.
尖齿拟水龙骨 jian chi ni shui long gu
Rhizome long creeping, 3-4 mm in diam., sparsely scaly and with whitish bloom; scales brown, ovate-lanceolate, base broad and peltate, margin sparsely toothed, apex acuminate. Fronds remote. Stipe straw-colored, 10-15 cm, scaly at base, glabrous upward. Lamina ovate lanceolate in outline, 40-50 × 15-25 cm. Lateral pinnae 15-20 pairs, sessile, ovate-lanceolate, 10-15 × 1.5-2.5 cm, base rounded, margin serrate or denticulate, apex acuminate; terminal pinna distinct; veins anastomosing to form 2 or 3 areoles on each side of costa, each costal areole containing a simple free included veinlet, other free veinlet ending inside margin of lobes, visible on both surfaces. Lamina herbaceous, abaxially yellowish green, adaxially dark green, both surfaces glabrous except for minute scales abaxially. Sori orbicular, terminal on included veinlets of costal areoles, in 1 row on each side of costa, medial or slightly closer to costa, superficial.
Epiphytic on tree trunks or on rocks; 2300-2700 m. Guangxi, Guizhou, Xizang, Yunnan [Bhutan, NE India, Myanmar, Thailand, Nepal].
The epithet "argutum" was first used by Wallich (Numer. List, no. 308. 1829, nom. nud.).