8. Lepisorus tosaensis (Makino) H. Itô, J. Jap. Bot. 11: 93. 1935.
阔叶瓦韦 kuo ye wa wei
Polypodium tosaense Makino, Bot. Mag. (Tokyo) 27: 127. 1913; Lepisorus infraplanicostalus (Hayata) Ching; L. paohuashanensis Ching; L. sinicus Ching & Z. Y. Liu; Polypodium hoozanense Hayata; P. infraplanicostale Hayata; P. lineare N. L. Burman var. caudatum Makino; P. morii Hayata.
Plants 15-30 cm tall. Rhizomes short and decumbent, less than 3 cm, 2-3 mm in diam., apex densely scaly, remainder soon naked; scales basifixed, deep brown with paler margins, iridescent when young, lanceolate or broadly lanceolate, 2-3.5 × 0.7-1.1 mm; most lumina opaque, marginal 1 or 2 rows of cells brownish, transparent. Fronds clustered; stipe straw-colored, 1-3(-5) cm, 1-1.5 mm in diam.; lamina brownish or grayish green when dried, lanceolate or linear-lanceolate, both ends attenuate, (10-)13-20 × 1-2 cm, widest at middle, leathery, both surfaces glabrous, base cuneate, decurrent, apex acuminate; costa raised on both sides, veinlets obscure. Sori on distal half of lamina, costular, rarely midway between costa and margins, orbicular, 3-7 mm in diam.; paraphyses orbicular, brownish with central lumina small and opaque or iridescent with lumina large and transparent. Spore surface foveolate.
On tree trunks or rocks in forests, in limestone crevices; sea level to 1000 m. Anhui, Chongqing, Guangdong, Guangxi, Guizhou, Hunan, Jiangsu, Jiangxi, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, Zhejiang [Japan, Korea, Vietnam].
This is a very difficult species to define, and many specimens have been misidentified as Lepisorus thunbergianus. We found that L. tosaensis can be distinguished from L. thunbergianus by the short rhizome, iridescent young scales, and much larger transparent lumina of the leaf scales. This species is always distributed at elevations less than 1000 m, while L. thunbergianus is found at relatively higher elevations.
Lepisorus paohuashanensis differs from L. tosaensis by the much smaller fronds, 3-7 × 0.4-0.6 cm, but this is just an extreme form within variable populations.