二色瓦韦 er se wa wei

Polypodium excavatum Bory ex Willdenow var. bicolor Takeda, Notes Roy. Bot. Gard. Edinburgh 8: 279, 281. 1915; Pleopeltis bicolor (Takeda) Sledge.

Plants 15-30(-35) cm tall. Rhizomes creeping, strong, 3-4 mm in diam., surface exposed between scales, white farinose; scales closely appressed, bicolored, nearly black with much paler brown margins, broadly ovate-lanceolate, ca. 1 × 1 mm, margins brownish and with irregular sharp spines, apex acuminate; lumina fine and dense; scales at rhizome apex denser, lanceolate, 1-2 × 0.7-1.2 mm. Fronds closely spaced or remote; stipe (1-)2-3.5(-8) cm, robust, 1.3-1.5 mm in diam., sparsely scaly; lamina brownish or gray-green on both surfaces when dried, lanceolate, widest 1/3-1/2 from base, both ends attenuate, (8-)10-28(-35) × 1-4 cm, herbaceous or thinly papery, abaxially with sparse adnate scales, adaxially glabrous, base cuneate, long decurrent, margin flatly straight and entire, apex acuminate or obtuse; costa raised on both sides, veinlets normally obscure. Sori usually along distal half of lamina, or near end of lamina, closer to costa, elliptic or suborbicular, 2-5 mm in diam.; paraphyses black, suborbicular, 0.5-0.8 mm in diam., membranous, margins erose; central lumina large and transparent, with marginal lumina irregular, cell walls brown, thickened.

In rock crevices beside streams in forests, at roadsides on mountain slopes; 1000-3300 m. Guizhou, Sichuan, Xizang, Yunnan [N India, Nepal].

Lepisorus bicolor is very common in montane forests in SW China, particularly Yunnan. The rhizome scales are of two types: those on the mature rhizome are very small and closely appressed; those at the rhizome apex are much larger and lanceolate. The bicolored scales resemble those of the following species, but L. morrisonensis has the rhizome concealed by uniformly large scales with white, not brown, margins.

Christ (Bull. Herb. Boissier 6: 876. 1898) treated material of Lepisorus bicolor as Polypodium oligolepidum Baker.