瑶山瓦韦 yao shan wa wei

Polypodium kuchenense Y. C. Wu, Bull. Dept. Biol. Sun Yatsen Univ. 3: 276. 1932; Pleopeltis kuchenensis (Y. C. Wu) Á. Löve & D. Löve.

Plants 15-30 cm tall. Rhizomes long and creeping, flattened when dry, 3-5 mm wide, strong, persistently scaly; scales appressed, brownish, lanceolate, 3-5 × 1.3-2 mm, clathrate, membranous, margins slightly undulate; lumina subsquare, isodiametric. Fronds 1-2 cm apart; stipe straw-colored or brownish, 2-10 cm, 1-2 mm in diam.; lamina deep brown on both surfaces or abaxially greenish and adaxially grayish green when dried, broadly lanceolate, (12-)20-30 × 3.5-6 cm, widest 1/3-1/2 from base, normally membranous, less often herbaceous or thinly papery, scales not easily seen, base attenuate or abruptly attenuate, decurrent, margin flat, straight or slightly undulate, apex acute or long caudate; costa raised on both sides, veinlets obviously visible. Sori midway between costa and margins, orbicular or elliptic, 4-6 mm in diam.; paraphyses brown, orbicular, 0.4-0.8 mm in diam.; lumina large.

● On tree trunks, forests on wet rocky cliffs; 1200-1700 m. Guangxi, Guizhou, ?Taiwan, Yunnan.

A very rare and distinct species, distinguished by the broadly lanceolate fronds, large medial sori, and large, pale brown scales.

The occurrence in Taiwan is based on a single collection from 1940 (Imaseki 70500 (TNS)), and it has not been possible to relocate this taxon in Taiwan (Knapp, Ferns Fern Allies Taiwan, 464, 785. 2011).