100 THE VEGETATION OF TEMPERATE AND ALPINE SIKHIM. 



P. Stuartii, P. denticiilata, Si'c. In shallow streams various species of 

 Sedum of the section Rkodiola, and the golden Chrijsosplenium alteriu- 

 folium are common in the clefts of stones, partly submerged in the 

 Tvater. Near the camping-ground of Megu can be found a quantity of 

 Poli/poiiivm clathrafum, a fern separated by Clarke from P. lineare 

 which it superficially resembles. It is thin and flacid in texture and 

 dries black; the peculiarly-shaped scales covering the sori, which 

 suggested the trivial name, alone serve to readily distinguish it from 

 its congeners. Woodsia lanosa affects the same habitat. The latter is 

 by no means a common fern, and its minute size assists to make it 

 more difficult to find. Cnjptogramme crispa is another equally interest- 

 ing fern which is abundant in most parts of Sikhim between 13 and 

 15,000 feet. 



On leaving the Singalelah Range properly so called and en)er- 

 ging under the stupendous masses of rock which extend in all direc- 

 tions from Kanchanjingna, a remarkable change of scenery is experi- 

 enced. For a short distance the terraces are covered with a thick 

 turf of grasses and sedges, amongst which are innumerable plants of 

 Primula Stuartii and Anemone. The faces of many ri)cks are covered 

 with cushions of saxifrages growing in hard, moss-like clusters, 

 spangled with white and yellow flowers. Further on, the ground 

 is covered with enormous accumulations of boulders which support no 

 vegetation except humble mosses, which are perennially moist from the 

 water which trickles over the whole surface of the slopes. Sir J. D. 

 Hooker, in his admirable account of the Physical Geography of Sikhim, 

 thus explains the cause of this barren desolation: — " Glaciers again 

 descend to 15,000 feet in the tortuous gorges which immediately 

 debouch from the snows of Kanchinjingna, but no plants grow on the 

 debris they carry down, nor is there any sward of grass or herbage at 

 their base, the atmosphere immediately around being chilled by 

 enormous accumulations of snow, and the summer sun rarely warming 

 the soil." 



The presence of one plant alone in this and other similar places 

 prevent the imputation of almost absolute sterility which they would 

 otherwise deserve. This is the truly remarkable and unique plant 

 Rheum nohik, the gigantic rhubarb of Sikhim. It thrives best on 

 inaccessible ledges of precipices. As Sir J. D Hooker says, "it forms 

 pale pyramidal towers a yard high, of inflated reflexed bracts that 

 conceal the flowers, and, overlapping each other like tiles, protect them 

 from the wind and rain ; a whorl of broad green leaves edged with red 

 spreads on the ground at the base of the plant, contrasting in colour 

 with the transparent bracts which are yellow, margined with pink." 

 He considered it to be the handsomest herbaceous plant in Sikhim, and 

 mentions that the acid stems are eaten both raw and boiled, that they 



