No. XXIV.— ON THE FERNS OP THE SEYCHELLES AND THE 



ALDABRA GROUP*. 



By Carl Christensen, M.Sc. (Copenhagen). 



(Communicated by Professor J. Stanley Gardiner, M.A., F.R.S., F.L.S.) 



(Plate 25.) 



Read 6th June, 1912. 



On the suggestion of Dv O. Stapf, Keeper of the Herbarium and Library, Royal 

 Botanic Gardens, KeAV, I undertook the determination of a collection of ferns made in 

 the Seychelles by Professor J. Stanley Gardiner during the ' Sealark ' Expedition in 1908, 

 and the preparation of a complete list of the ferns of the Seychelles. It is true, the 

 islands are not a terra nova for pteridography ; nevertheless a revision of the fern-flora 

 of the islands was thought desirable so as to bring it into line ■with modern ideas of 

 pteridography. 



The ferns of the Seychelles have been dealt with twice by J. G. Bakerf, and later on 

 by M. Kuhn %, who published a list of the ferns occurring in the islands. Whilst Baker 

 knew 74 species of true ferns indigenous in the island, Kuhn enumerated 76 si^ecies, and 

 my list includes 78 species. 



It was an easy task to name the specimens in accordance with Baker's treatment, but 

 as my ideas of the delimitation of not a few species differ essentially from those of Baker, 

 who takes the species in a much broader sense, I examined the material critically and 

 compared it with specimens which the authorities of Kew kindly forwarded to me for 

 that purpose. For this my best thanks are due to Sir David Prain and Dr Stapf. As 

 will be seen, I do not agree with all of Baker's determinations, and therefore my list differs 

 in certain points from his. My nomenclature too is, of course, very different from his. 

 With few exceptions, I follow the nomenclature of my ' Index Filicum,' which is quoted 

 under each species. In that work the essential synonyms and references will also be 

 found, wherefore it is unnecessary to repeat them here. 



So far as is known, the Seychelles are inhabited by 78 species of ferns, all but one 

 {Ceropteris Crt^oj«eZa*?o*, which probably is introduced) indigenous in the islands. All 

 these species were collected in the higher islands, Mahe and Silhouette ; three or four 

 were also found in Bird Island and Long Island. No fern is known from the other 

 islands (Praslin, La Digue, and Curieuse). Prof. Gardiner has added four species to 

 the fern-flora of the islands. 



* Reprinted from Trans. Linn. Soc, ser. 2, Bot., vol. vii. pp. 409-25, pi. 45, 1912. 



t J. G. Baker: "On the Seychelles Fern-Flora," in Trans. R. Irish Acad. vol. sxv. (1875), pp. 509-518, 

 tabb. 28-31 ; ' Flora of Mauritius and the Seychelles ' (1877). 



J M. Kuhn : Cryptogama) vasoulares, in ' Botauik von Ost-Afrika ' in Von der Decken'e Reisen, vol. iii. part 1 

 (1879), pp. 68-60. 



SECOND SERIES— ZOOLOGY, VOL. XV. 52 



J/o" 



