THE FERNS OF NORTH-WESTERN INDIA . 
19! 
Going through the collection of Ferns in the Kew Herbarium, I have found 
no difficulty in distinguishing between these four species — 
1. A. auriculatum , Swartz. 
2. A. marginatum , Wall. 
3. A. Uritum , Don. 
4. A. obliquum , Don. 
-= ri. ccvspitosum > Wall. 
I have gathered only the two last of these, and taking them only, whether 
in the field or in the Herbarium, I think it would not occur to a casual obser- 
ver that they were so neatly 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 he. 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 auricled pinnae ; but 
that is the almost invariable characteristic of the snbgepus (or genus) Polysti- 
chum. I take it that it was the result of No. 1 having been given the specific 
name — auriculatum , by Swartz that species subsequently described and dif- 
ferently named by other collectors and authors, but which also were auricled, 
were afterwards, by authors who had not gathered the plants, united with, or 
given as mere varieties of the first described plant, A. auriculatum . 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 £ 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. II., Jany. 7th), and quite 
bipinnate, though the secondary rhachis is winged in the upper part of the 
pinnae. The pinnules are rhomboidal -ovate, sharply and stiffly spined on the 
apex, and once or twice spined on the sides. 
My Chamba 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. 
