﻿MR. JOHN SCOTT ON THE TREE FERNS OF BRITISH SIKKTM. 35 



3000-6000 



most 



and at the lower and higher elevations noted ahove it is but sparingly distributed. 



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The extreme forms when seen growing are so very dissimilar in general appearance 



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that, but for the many intermediate forms, they might he regarded as specifically distinct. 

 It is the first of the tree ferns which greets the eye in the ascent of these hills by 

 the Ganges and Darjeeling road, as at Kursiong, where there are several fine groves 

 and many isolated plants. These, however, rarely exceed 20 feet in height ; and it 

 is only at elevations of 5000 feet and upwards that we find them with fully de- 

 veloped, simple, rarely forked caudices, 30-50 feet high. In one specimen which 

 Mr. Gammie was good enough to measure for me on Sinchal, at an elevation of 5200 

 feet, the caudex w as 43 feet high and 7 feet in circumference near the base. I pre- 

 sume, however, that the girth-measurement was taken round the large cone of adventitious 



roots, as the thickest specimen which I have seen measured only 4^ feet round the 

 clean caudex. 



2. A. coNTAMiNANs, Wall. Stipes and rachides paleaceous at the base, purplish brown, 



glossy, aculeate, with short prickles tipped with a gland : fronds ample, coriaceous, 

 glabrous, black-green above (when dry), glaucous beneath; j^rimary pinnce 2 feet 

 and more long, oblong-ovate, acuminate; pinnules sessile, 4-5 inches long, J to 

 nearly 1 inch wide, deeply (nearly to the costule) pinnatifid, linear -oblong, sub- 

 falcate, entire, the fertile ones often more contracted, with margins (when dry) 

 revolute, obscurely crenate; veins once or twice forked; sori nearer the costule 

 than the margin, a minute shallow-lobed and cut membrane surrounding the base of 

 the receptacle after the capsules are fallen. — Syn. Pil. p. 41 ; A. contaminans. 

 Wall. Cat. in Index ; Bedd. Pil. Brit. Ind. t. 85 ; Folypodium contaminans. Wall. 



w ■ 



in herb. 1823 ; Cat, n. 320. " Paluh-doon " of the Lepchas. 



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Var. jS (A. Bnmonianay Wall. Cat. n. 7073 B.) unarmed, stipes densely pulverulent 



segments more elongated, 5-7 inches long, j-l inch wide, obtuse ; sori extendin 



a 



nearly to the apex of the segments. — A. glaucescens, Wall. n. 7074 ; A. TFallichiana, 

 Pr^sl, Tent. Pterid. p. 62. " Paluh '* of the Lepchas. 



The normal form of this species is a rare plant in Sikkim, becoming more abundant 

 in the Khasia hiUs, and frequent in the Malayan peninsula and islands of the archi- 

 pelago. The var. j3, on the other hand, is one of the commonest of the tropical tree 

 ferns of Sikkim, equally abundant also in the Khasia and adjoining hill-ranges, ex- 

 tending to Burmah, the Malayan peninsula and islands. In Sikkhn its altitudinal 

 range is from about 2000-3000 feet : var. a rarely exceeds 25 or 30 feet in height, and 

 from 3-4 feet in circumference : var. /3 is altogether more graceful, with a tall and 

 slender stem, from 30-50 feet high, and 1-3 feet in circumference, conspicuously and 

 regularly marked with the large scars of the fallen fronds. The base of the stipes 

 and young unfolding fronds are in both densely clothed wath long glossy chestnut 



coloured scales, and throughout covered (more densely in var. /3) with a yellowish grey 



puberulous matter. The fronds are from 10-18 feet long and 4-8 feet wide. The 



F 2 



