158 
THE VEGETATWH OF THE ZEMU 
grazing ground to the south from the Tibetan to the north. This 
cannot be the rule now as we found Khambajong herdsmen at the 
extreme western part of Llonakh,. 
On the 3rd S. devoted his time to the marsh land which is of 
a type not seen elsewhere in Sikkim and contained Hi'p'purisy 
Glaux, and other plants not previously recorded from this side of 
the Himalaya. Meanwhile C. as the better mountaineer left early 
to ascend the Naku La. Neither of us and few of the coolies 
suffered much at any time from the altitude. C. was sick once or 
twice on the tour when 16,000 feet was first reached, while S. did 
not experience more than a tightness round the head. Above 16,000 
feet the chief disability was scantness of breath and the loaded 
men could only make a few yards at a time. 
The marshea are not productive of many species and the few 
available are mostly of West Himalayan and Tibetan type: — Ramin^ 
cuius aquatilis in the pools, Dilo'phia salsa, a plant of the Tibetan 
salt marshes. Primula tihetica in profusion and fine clumps of 
yellow Pedicularis. Grasses and carices were disappointingly few 
and scarcely in flower. The slopes immediately above the river 
have a very piebald appearance — the dark tufts of juniper and 
rhododendron occupy in patches about one-sixth of the area, while 
large moraines and scattered boulders cover the rest. Among these 
stones a few hardy xerophytes are to be obtained but much of the 
area is quite barren. The juniper mounds shelter one or two species 
which do not dare to face the conditions unprotected. Callianthe- 
mum we found invariably thus. 
Meanwhile C. had a long and arduous march to the Naku La. 
This is over 18,000 feet and is practicable for ponies and yaks. It 
is the easiest means of access to Llonakh — permissible, however, 
only to Tibetans. The river valley is a succession of flats inter- 
rupted by moraines and defiles. Most of the side streams enter on 
the left bank, only one of any size from the right which is much 
shut in with sieep stony hills. The main stream comes from the 
south-west side of the Chumiumo glacier. The vegetation corre- 
sponds closely with that of the lower reaches except near the top 
of the pass where several interesting plants of Tibetan type were 
secured, 
A 
The 4th was a drizzling day with occasional showers of sleet. 
Fording the icy Naku Chu opposite Teble, three to four feet deep, 
w’e traversed the long line of hills and moraines which lead to 
the Ghoraphu valley. Next day we entered the Lungma Chu 
(Langbu Chu) valley, followed it up for four miles where we 
