72 DR. THOMSON'S MISSION TO THIBET. 
flowers in dense racemes upwards of a foot long. This, which is 
probably the 4. pyramidalis of Royle (for I found it last year in fruit in 
Kunawur) as well as the splendid species of Ornithogalum (?) of Fal- 
coner, noticed by him, appears to belong to the genus Eremurus of 
Bieberstein, and though differing in one or two trifling points from 
the description, is perhaps not specifically distinct from the Caucasian 
and Altaic species. As I advanced to the south, new plants (principally 
ordinary Himalayan forms) appeared in succession : first came Quercus 
lanata, then the common Andr (Pieris ovalifolia), and others 
followed, till at last the elevation became too low for even these, and all 
gave place to ordinary tropicalforms. The valley of the Chenab being 
enclosed on both sides by high mountains, I descended into it from a 
height of 8,000 feet, and next day ascended again to a cool climate, so 
that I had only one day of heat. The rapidity of the descent and ascent 
gave me good opportunity of observing the gradual change of vegeta- 
tion ; but so much depends on the exposure, and the more or less wooded 
nature of the mountain-side, that no precise limit can be laid down 
between temperate and tropical vegetation, nor can fixed heights be 
stated at which plants cease or begin to grow. Even on the river 
bank (2,500 feet) certain plants of temperate climates were common, 
especially on the south side, where they found more shade; but the 
greater part of the plants were tropical and in general the same as 
those of the valley of the Sutlej; Dalbergia Sissoo, Rottlera tinctoria, 
Adhatoda, Acacia Lebbek, Bauhinia, and Colebrookia being the most 
common. As might be expected, too, the productions of the plains of 
the Punjab, which do not occur further east, occurred here instead of 
others which do not extend west; thus Zizyphus microphylla replaced 
Z. Jujuba, and Acacia modesta and a prickly Celastrus other species. 
Besides the ordinary tropical forms, one or two anomalous plants 
occurred, of which a prickly Astragalus, perhaps the Kashmir species, 
puzzled me most : I found it however afterwards still lower, and nearer 
the plains, within thirty miles of Jamu. Olea cuspidata and a white 
Kashmir Daphne (D. coriacea, Royle?) seem to affect a dry climate. 
The former is common from the Indus and extends as far as Kamaon, 
but probably only in the drier parts near the snow. The Daphne 
is plentiful on the lower Indus (below Iskardo) as well as in Kashmir, 
and in all the hot valleys near the Chenab, and it extends as far 
east as Lower Kunawur, not however apparently descending on the 
