ICONES FILICUM SINICARUM 
PLATE 163 
ONYCHIUM TENUIFRONS Ching 
POLYPODIACEZ 
ONYCHIUM TENUIFRONS Ching, Lingnan Sci. Journ. 13: 500 (1934). 
Onychium japonicum var. Delavayi Christ, Bull. Soc. Bot. France 52; Mém. I. 60 (tg05) 
Onychium lucidum Ktimmerle, Amer. Fern Journ. 20: 135 (1930); C. Chr. Ind. Fil. Suppl. III. 133 
(1934) pro parte. 
Rhizome short-creeping, rather thick, densely clothed in pale brown, linear-subulate 
scales; fronds subcaespitose, subdimorphous, stipe firm, erect, straminous, 6-15 cm long, 
flexuose, naked, lamina oblong-lanceolate, 15-25 cm long, tripinnate at base, bipinnate 
towards acuminate apex; pinnae 5-8-jugate, petiolate, oblique, 5-r0 cm long, lanceolate; 
pinnules rhombic, pinnate; segments 3-5-jugate, linear, 5-7 mm long, 15 mm broad, 
acuminate, margin obscurely denticulate; texture rigidly coriaceous, subnitente, glabrous 
on both sides; veins prominently raised above, one to each segment, pinnate; sori 3-5 mm 
long, indusium gray, reaching costule from both sides, margin deeply erosed; sterile leaves 
on much shorter stipe, with broader and confert pinnules and segments. 
Yunnan: Shweli-Salween divide, G. Forrest 24175 (type), July. 1924; Loko Chan, 
Delavay 1715; Tapin-tze, Delavay $2; Ty-ly, Ducloux 5821; Tai-tsien-teen, E. E. M aire, 
Sept. 1913; Tchong-san, Ducloux 3372, Nov. 2, 1909; Nieou Ko Chan region, Pin-chow, 
Ducloux 6973. Szechwan: On the Yunnan border, W. P. Fang 9191, Oct. 20, 1930. 
This endemic species is closely related to O. japonicum Kze. differs from that or 
other related species in oblong-lanceolate and once less pinnate fronds, subcaespitose 
leaves, pale brown scales on rhizome, more or less denticulated ultimate segments and the 
deeply erosed margin of indusium, which last character has so far been known only in 
O. melanole pis (Decsn), a species from Abyssine. 
Plate 163. Fig. 1. Habit sketch (natural size). 2. Portion of sterile frond, showing venation 
(x 10). 3. Soriferous segment, showing attachment of sori and indusium with erose-dentate margin (x 
16). 4. Scale from rhizome (83 27). 
