FLORA OF TIBET OR HIGH ASIA. 219 
and plants inhabiting the moist ground near the shores of the 
lakes are also fewer than might have been expected. The genera 
Ranunculus, Selinum, Cremanthodium, Pleurogyne, Gentiana, 
Pedicularis, Polygonum, and Triglochin are represented by 
moisture-loving species. Some of the sedges and grasses are most 
likely confined to wet ground, but evidence is wanting. Phrag- 
mites communis may be classed here. Zannichellia palustris, 
mentioned at p. 142 as having been found by Hooker at Bhomtso, 
proves to be Potamogeton pectinatus. 
Buxzots and Tuserovs Prants. 
The small number of species coming under this head is one of 
the most inexplicable facts connected with the vegetation of 
Tibet, though it is also true that bulbous plants are rare 
among the high-level plants in all parts of the world. Gagea 
pauciflora, collected by Rockhill only, and three or four species of 
Allium are the only bulbous plants in the collections. One species 
of Allium—A. Semenovi—is widely distributed and very abundant 
in some localities. This species was collected by Hedin, and 
Wellby and Malcolm, and it is probably the one referred to by 
Rockhill as being very plentiful at altitudes above 15,000 ft., 
though they sought it in vain below this level. Wellby and 
Malcolm, who had to subsist largely on this onion during part 
of their journey, note that it was commonly distributed between 
88° 20' and 96° along the thirty-fifth parallel. A. Jacquemonti, 
collected by Strachey and Winterbottom in W. Tibet, has also 
an edible bulb. 
ANNUAL PLANTS. 
The conditions are not favourable to the development of 
“annual” plants—that is to say plants which have only one 
growing season, springing from seed and flowering within a few 
weeks, or at all events before the end of season. The following 
appear to belong to this category :—Hypecoum leptocarpum, 
Pleurogyne brachyanthera, Gentiana tenella, G. humilis, G. 
Thomsoni, G@. aquatica, G. Rockhilli, Salsola collina, S. Kali, 
and Halogeton glomeratus. All of these plants are apparently 
very rare in Tibet, and, with one or two exceptions, represented 
in only one of the collections. Thus Gentiana tenella : | only 
one or two specimens seen, although I looked closely” (Pike). 
G. humilis: ‘very scarce”? (Pike). Pleurogyne brachyanthera: 
“the only specimen I have seen” (Pike)—a diminutive plant 
bearing one flower. 
