网眼瓦韦 wang yan wa wei

Polypodium clathratum C. B. Clarke, Trans. Linn. Soc. London, Bot. 2: 559. 1880; Lepisorus clathratus var. namegatae Sa. Kurata; L. namegatae (Sa. Kurata) Ching & Y. X. Lin; L. nepalensis K. Iwatsuki; L. petiolatus Ching & Y. X. Lin; L. pseudoclathratus Ching & S. K. Wu; L. soulieanus (Christ) Ching & S. K. Wu; L. variabilis Ching & S. K. Wu; Platygyria kongtingensis Ching & Y. X. Lin; P. muliensis Ching & S. K. Wu; P. soulieana (Christ) X. C. Zhang & Q. R. Liu; P. variabilis Ching & S. K. Wu; Pleopeltis clathrata (C. B. Clarke) Beddome; P. clathrata var. namegatae (Sa. Kurata) Ohwi; Polypodium soulieanum Christ.

Plants 5-17 cm tall. Rhizomes long and creeping, 1.5-3 mm in diam., densely scaly; scales ± deep brown, lanceolate to ovate, 3.5-7 × 0.7-1 mm, brittle, transparent, base ovate, margins shortly dentate, apex shortly acute; basal lumina isodiametric, ± square, distal ones subrectangular. Fronds remote or ± closely spaced; stipe straw-colored, 0.7-6.3 cm, slender, less than 1 mm in diam.; lamina greenish or brownish green on both surfaces when dried, lanceolate, both ends attenuate, 4-20 × 0.8-1.5(-2) cm, widest at or below middle, herbaceous to submembranous, almost glabrous, base cuneate, slightly decurrent, margin flat and straight, apex bluntly acuminate to gradually long attenuate; costa slightly raised on both sides, veinlets ± visible. Sori along 7/8 of length, midway between costa and margins, suborbicular, 2-2.5 mm in diam.; paraphyses dark brown, stellate or lanceolate, margin with long spines; lumina large and transparent. Sporangia leptosporangiate: dehiscent with narrow annulus of very thick-walled cells, or platygyroid: indehiscent with wide annulus of thin-walled cells.

On tree trunks in broad-leaved evergreen forests, in rock crevices on open slopes, or stony riverbanks; 2000-4300 m. Guangxi, Qinghai, Sichuan, Xizang [Bhutan, India, Japan, Kashmir, Nepal].

A very wide interpretation has been taken for Lepisorus clathratus ± following Fraser-Jenkins (Taxon. Revis. Indian Subcontinental Pteridophytes, 41-42. 2008) as accepted by Li Wang et al. (Phylogeography of the Sino-Himalayan Fern Lepisorus clathratus on "The Roof of the World." 2011. PLoS ONE 6(9): e25896. doi:10.1371/journal.pone. 0025896; accessed 28 May 2012).

Lepisorus soulieanus had been placed in a different genus, Platygyria, on the basis of the distinctive sporangium annulus of broad, pale, thin-walled cells, but this is not a consistent feature with some collections showing a range from these to normal leptosporangiate annuli. There are no other characters that allow a clear separation between the two taxa. Lepisorus petiolatus was primarily separated on the basis of the long slender stipe, but this also is a very variable feature with no obvious discontinuity to justify the recognition of distinct taxa.