- 347 — 



Although the specimen is sterile it doubtless belongs to this species, 

 that is distinguished by a spiny rhizome and the pinnæ articulated to the 

 rachis. The specimen differs from the typical form by having the pinnæ 

 irregularly toothed. Some authors consider S. aculeata an anormal form 

 of S. sorbifolia sp. coll., others of Si palustris. 



Area: Tropical Asia. 



38. Onychium siliculosum (Desv.) G. Chr. Ind. 469; O. auratum Klf. ; 

 Christ, 1. c. 106 (no. 68). 



39. Adiantum flabellulatum L.; G. 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. Bonii 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. Bonii, 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 cm. 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 

 l*/a 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 

 semicircular!, 1 — \ l h 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. Bonii 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. 



