THE FERNS OF NORTH-WESTERN INDIA, 4frl 



Going through fche collection of Ferns in the Kew Herbarium, I have found 

 BO difficulty in distinguishing between these four species — 



1. A. auriculatum^ Swartz„ 



2. A, marginatum^ Wall. 



3. A. lentum, Don. 



4. A, oUiquum^ Don. 



^= A. cmspitosum, Wall, 



I have gathered only the two last of these, and taking them only, whether 

 ill the field or in the Herbarium, I think it would not occur to a casual obser- 

 ver that they were so nearly connected as to be merely varieties of another 

 fern ; they are as different from each other as any two species of the same 

 genus can be. But large fronds of No. 4, as seen in a Herbarium, have a 

 superficial resemblance in cutting to fronds of No. 1 ; and there is at least one 

 character in common between No. 4 and No. 2. Also there is one character 

 common to all four species, which is that they all have aurioled pinnae ; but 

 that is the almost invariable characteristic of the subgenus (or genus) Folysii- 

 chum. I take it that it was the result of No. 1 having been gi^en the specific 

 name — aurkulatum, by Swartz that species subsequently described and dif- 

 ferently named by other collectors and authors, but which also were aurioled, 

 were afterwards, by authors who had not gathered the plants, imited with, or 

 given as mere varieties of the first described plant, A. aurkulatum. Had 

 Swartz named his species after any other feature of the plant than its auricle, 

 or after, say, " The man in the street," this confusion between the four species 

 might never have arisen, and certainly could not have between Nos. 3 and 4 

 at least. The chief differences between Nos. 1 and 2 have been mentioned 

 above, and the distinguishing characters of Nos. 3 and 4 will be mentioned in 

 their proper places. Returning to No. 2, A. marginatum, I have to add that I 

 have the simple form with fronds varying in size from 4 in. 1. by f in. br. 

 to 14 by 4| inches ; and one incomplete frond from Sikkim must have been at 

 least 20 inches in length ; in these the auricle is not free, and the rest of the 

 pinna is not very deeply lobed. The more compound form has fronds not 

 longer than the other, but often much broader, — 9 inches broad in one specimen 

 in Kew, from the Rattong Valley in Sikkim (J. D. H., Jany. 7th), and quite 

 bipinnate, though the secondary rhachis is winged m tlie upper part of the 

 pinnae. The ]>innules are rhomboidal -ovate, sharply and stiffly spined on the 

 apex, and once or twice spined on the sides. 



My Ohamba specimens, from Mr. McDonell, are whole plants, with three to 

 seven fronds each, and they show the plant to be dimorphous, with the fertile 

 fronds considerably smaller than the sterile, but with the stipes not much 

 shorter. 



