5. Asplenium griffithianum Hooker, Icon. Pl. 10: t. 928. 1854.
厚叶铁角蕨 hou ye tie jiao jue
Asplenium baibarense Tatewaki & Tagawa; A. holophyllum Baker; A. iridiphyllum Hayata; A. nakanoanum Makino; A. scolopendrifrons Hayata; Diplazium iridiphyllum (Hayata) Hayata.
Plants 15-25(-30) cm tall. Rhizome erect, short, apex densely scaly; scales blackish brown, narrowly triangular or ovate, margins denticulate. Fronds caespitose, simple; stipe stramineous, very short or absent, 0.4-2.5 cm; lamina lanceolate, 15-25 × (1.5-)1.9-2.5(-3.9) cm, usually ca. 10 × longer than wide, base gradually decurrent and forming narrow wing on stipe, margin entire or sinuate in basal part, upward irregularly sinuate-crenate, and often notched, apex acuminate or acute. Midrib stramineous, not distinctly raised abaxially, adaxially raised; veins obscure, 1-forked. Fronds fleshy, grayish green when dry, with minute brown triangular to stellate scales, subglabrous when old. Sori brown, linear, 5-9(-11) mm, starting close to midrib at an angle of (30°-)45°-50°(-65°), and up to 2/3 width of lamina; indusia gray to yellowish brown, linear, entire, opening toward midrib, persistent. Spores with many perforations in outer subechinate-lophate perispore.
On tree trunks or wet rocks in forests; 100-1600 m. Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Sichuan, Taiwan, Xizang, Yunnan [Bhutan, India, Japan, Myanmar, Nepal, Vietnam].
Plants from Sikkim, India, were reported to be diploid hybrids by Bir (Curr. Sci. 29: 445-447. 1960) and by Mehra (Res. Bull. Panjab Univ. Sci., n.s., 12: 139-164. 1961), but our recent FCM results show that at least the Guizhou plants are polyploids (12-14x).
In its present circumscription this species includes different taxa that need further study. Asplenium ×xinyiense Ching & S. H. Wu (Bull. Bot. Res., Harbin 9(2): 82. 1989, pro sp.), a plant with abortive spores described from SW Guangdong, is a hybrid between either A. griffithianum or A. loxogrammoides and A. wrightii. These species grow intermixed on cliffs near the type locality of A. ×xinyiense.