FLORA OF TIBET OR HIGH ASIA. 207 
towards the Keria mountains, on the mud-beds (commonly 
called loess) along the Hoangho, and the river-valleys of the 
Amdo and in Tsaidam, the flora ealls to mind that of the ad- 
Joining regions of Mongolia; but in the alpine zone the flora is 
more like that of the mountains of North Central Asia, and the 
resemblance becomes greater in the drier areas. 
“Forests are altogether absent from the mountain-ridges of 
Chinese Turkestan and the confines of Mongolia—one or two 
small areas on the eastern Nan Shan mountains excepted. 
“In the Keria mountains also the few shrubs which occur, 
namely, Tamarix Pallasii, Myricaria germanica, Caragana 
pygmea, Hedysarum, Nitraria, and Lycium turcomanicum, are 
met with only in the deepest ravines. 
** Descending the northern slopes of Altyn Tag, between 9000 
and 7000 feet above the sea, we find Tamarix laxa, Populus 
diversifolia, Ephedra, Halostachys orgyalis, Zygophyllum, Reau- 
muria, Kalidium, Karelinia, Phragmites, Lasiagrostis, as well as 
some of those mentioned above; and at the foot of the mountains 
Alhagi camelorum aypears. 
“In the desert-valleys between the Nan Shan ridges, the flora, 
sparse and grey of aspect, is composed of Salsola abrotanoides, 
Sympegma Regeli, Astragalus monophyllus, Stellera Chamajasme, 
Potentilla fruticosa, Festuca, and, in the wetter places, Hedysarum 
multijugun, Tamarix elongata, Comarum Salessowit, Caryopteris 
mongolica, Hippophaé, Calimeris alyssoides, Salix, Mulgedium 
tataricum, Feheum spiciforme, Gentiana barbata, Adenophora, and 
other species of Potentilla. 
“The alpine meadows on the Keria mountains are small 
and are inhabited by few species, among them dwarf STASses, 
Artemisia parvula, species of Astragalus, Allium, Tris, Statice, 
Saxifraga, Androsace, and others, which are more Common in 
Northern Tibet. The appearance of the alpine meadows of 
Nan Shan, situated in a belt between 11,000 and 13,000 ft., is a 
little better, but even here they are by no means extensive, 
and are frequently interrupted by broken rocks and stony 
declivities. Here grow about a dozen species of Oxytropis 
and Astragalus, among them O. tragacanthoides, Sterigma 
sulfureum, Orepis Pallasii, Allium Szovitsianum, Potentilla 
multifida. And at a higher elevation, on the northern side up 
to 13,700 ft., on the southern up to 15,000 ft., are found scattered 
specimens of Saussurea sorocephala, Leontopodium alpinum, 
