144. Polystichum wattii (Beddome) C. Christensen, Index Filic. 98. 1905.
细裂耳蕨 xi lie er jue
Aspidium wattii Beddome, J. Bot. 26: 234. 1888; Lastrea wattii (Beddome) Beddome.
Plants evergreen. Rhizome ascending to erect, short, rhizome apex and stipe base densely scaly; large scales opening, dark brown, ovate or narrowly ovate, up to 1 cm × 5 mm, shallowly erose, acuminate. Fronds 30-85 cm; stipe stramineous, 3-25 cm, 1-4 mm in diam. at base. Lamina tri- to tetrapinnatilobate, green or dark green when dry, adaxially darker, narrowly elliptic-lanceolate, 20-60 cm, 3-20 cm wide at middle, 2-7 cm wide at base, acuminate; rachis stramineous, without proliferous bulbils, sparsely covered with linear scales. Pinnae 25-40 pairs, mostly alternate, slightly ascendant, sessile, lanceolate and often slightly curved upward and falcate, middle pairs 1.5-13 × 0.5-2 cm, acuminate to caudate and long acuminate. Pinnules 5-15 pairs on middle pinnae, obliquely ovate, alternate, slightly ascendant, shortly stalked, acute; basal acroscopic pinnules largest; secondary pinnules obliquely rectangular or obovate, bases shortly stalked or narrowly cuneate and decurrent, apices acute or slightly obtuse, without spinulose tips; basal acroscopic secondary pinnules largest, apices forked-lobed or pinnate and forming 1 or 2 pairs of free obovate lobes, margins of other secondary pinnules entire or with 2 or 3 shallow lobes; costa green, abaxially scaly; scales similar to rachis scales but smaller; frond texture thinly papery; venation indistinct, 1 per lobe, reaching tip of lobe. Sori small, abaxial on veinlets, located at middle of secondary pinnules or lobes; indusia present, brown, small, entire, ca. 1/2 width of lobes. Spores semicircular in equatorial view, elliptic in polar view; perispore sculpturing reticulate with large lumina.
Rocks and rock crevices in montane broad-leaved evergreen forests; 1400-2000 m. SE Xizang (Mêdog), NW and W Yunnan (Dulongjiang region, Gaoligong Shan, Nushan) [N India, N Myanmar].
Polystichum wattii has been placed in P. sect. Micropolystichum by Fraser-Jenkins (Himalayan Ferns (Guide to Polystichum), 7. 1997). It might be a member of P. sect. Hypopeltis.