347 493 
Although the specimen is sterile it doubtless belongs to this species, 
that is distinguished by a spiny rhizome and the pinne articulated to the 
rachis. The specimen differs from the typical form by having the pinne 
irregularly toothed. Some authors consider S. aculeata an anormal form 
of 8. sorbifolia sp. coll., others of S. palustris. 
Area: Tropical Asia. 
38. Onychium siliculosum (Desv.) C. Chr. Ind. 469; O. auwratum KIf.; 
Christ, 1. ¢. 106 (no. 68). 
39. Adiantum flabellulatum L.; C. Chr. Ind. 26; A. Bonii ex parte 
Christ, 1. c. 106. 
Nipple, 2000 ft., on rocks in open jungle (no. 678). 
Area: Tropical Asia and northwards to Japan. 
40. Adiantum fragiliforme n. sp. 
A, Bonii ex parte Christ, 1. c. 106 (non Journ. de Bot. 8: 150). 
Although I have not seen the original A. Bondi from Tonkin I am 
convinced, after a close comparison of the Koh Chang plant with Christ’s 
original description, that our plant can not be A. Bondi. It belongs to a 
group of which several species have been described in recent years, but 
as it differs from all these in some points I propose it as new. 
Rhizomate breve, erecto, dense radicante. Stipitibus atro-castaneis, 
nitidis, strictis, ad 10 cm. longis. Lamina ambitu late ovata, 10—13 cm. 
longa et lata, tripinnata, glaberrima, rigida, infra paulo glaucescente. Pinnis 
primariis utrinque 3—4, 4—8 cm. distantibus, infimis maximis, longe 
petiolatis (petiolo 3—4 em. longo), 6—8 cm. longis. Pinnis secundariis 
in pinna infima 2-jugis, in pinna sequente unijugis; pinnis superioribus 
atque terminali simpliciter pinnata. Segmentis breve petiolulatis (petiolo 
11/2 mm. longis), ad petiolum distincte articulatis et facile decedentibus, 
5—8 mm. longis et latis, basi aequaliter cuneatis vel saepe utrinque rotun- 
datis, margine exteriore integro vel obsolete dentato indivisis vel plus 
minusve profunde bi- (raro tri-) lobatis, segmento terminali vix majore. 
Soris in segmento uno vel binis, rarissime ternis; margine segmenti 
sorifero paulo emarginato. Indusio atro-brunneo, subquadrangulari vel saepe 
semicirculari, 1—11+/2 mm. lato. 
Koh Chang, Klong Son, 1000 ft., on rocks in the jungle (no. 677). 
This species seems to differ from all species of Adiantum from 
tropical Asia by its distinctly articulated segments, which in the dried 
specimens are very apt to fall off as in the West Indian A. fragile Sw., 
a species with different sori. In general habit, branching and shape of 
segment our new species is very similar to A. Wattii Bak., which species 
Beddome (Suppl. 18) has referred to A. capillus veneris as a variety. 
If he is right in this our species is not A. Wattii. A. Bonti is described 
as having the stipe scarcely glossy, segments not articulated to the petiole, 
the terminal larger than the lateral ones, sori reniform and 3—5 to a 
segment. By these characters and in others A. Bonii is certainly widely 
different from A. fragiliforme. 
