8. Elaphoglossum Schott ex J. Smith, J. Bot. (Hooker). 4: 148. 1841.
舌蕨属 she jue shu
Authors: Prof. Fuwu Xing, Wang Faguo & John T. Mickel
Plants small to medium-sized, epiphytic, rarely terrestrial or epilithic. Rhizome shortly to long creeping, bearing roots ventrally and fronds in 2 dorsal rows, dictyostelic, scales narrow or broad, usually cordate, dark or pale, margins bearing short teeth or hairs, often glandular. Fronds tufted, rarely remote, dimorphic, variously scaly or glabrous; stipes usually terete, articulate or subarticulate to scaly phyllopodia; sterile lamina simple, entire, mostly thick and leathery, margin often thin and colorless to stramineous, strongly thickened, narrowly revolute; veins mostly immersed free, simple or forked and parallel almost to margin, sometimes connected by an intramarginal vein at their tips, rarely copiously anastomosing; fertile lamina often longer, contracted and with longer stipe. Sporangia acrostichoid, entirely covering abaxial surface of lamina, exindusiate, paraphyses lacking, annulus longitudinal, interrupted, of ca. 12 thickened cells. Spores brown, elliptic, monolete, with a thick folded perispore. n = 41.
More than 400 species: throughout wetter parts of tropical and temperate zones, with greatest diversity in the Andes of South America; six species (one endemic) in China.
Knapp (Ferns Fern Allies Taiwan, 272. 2011) records Elaphoglossum commutatum (Mettenius ex Kuhn) Alderwerelt (Malayan Ferns Fern Allies Suppl. 427. 1917; Acrostichum commutatum Mettenius ex Kuhn, Ann. Mus. Bot. Lugduno-Batavi 4: 292. 1869; E. subellipticum Rosenstock) from Taiwan. It would key out below as E. marginatum but differs by the rhizome scales, which have the apex hairlike, twisted and often tangled, not acuminate or attenuate.
