208 MR. W. B. HEMSLEY ON THE 
Thylacospermum, Sedum quadrifidum, Draba alpina, D. himalacca, 
and Werneria nana. 
‘‘Some parts of Tsaidam, which is protected on all sides by 
high mountains, supports a more vigorous vegetation, although 
the species represented are not numerous. In the swamps at 
the foot of the mountains there are Scirpus maritimus, Typha 
stenophylla, Hippuris vulgaris, and Utricularia, with Elymus 
sibiricus on their margins. In the salt plain, among the pools 
and marshes, many large areas are covered with Arundo Phraq- 
mites (Phragmites communis); the streams are fringed with 
shrubs of Myricaria germanica, Nitraria, Lycium turcomanicum. 
In the salt-marshes occur Kalidium gracile, Salsola Kali, Halo- 
geton, and Kochia mollis; in the drier areas grow Nitrarta 
Schoberi var. orgyalis, Eurotia ceratoides, Atraphaxis lanceolata, 
Reaumuria soongorica and R. trigyna; and on the dunes o! 
shifting sand, Haloxylon Ammodendron, Hedysarum Arbuscula, 
Psamma villosa, Apocynum venetum, Tamariz Pallasit, T. laxa, 
and Artemisia campestris are the predominating plants. On the 
slopes of the Koko Nor mountains extending into Tsaidam is 
a forest of Juniperus Pseudo-Sabina; along the rivers Bais and 
Nomochu, towards the Tibetan froutier, Tamarix Pallasii attains 
a height of nearly twenty feet, and Spherophysa salsula, Calhi- 
gonum mongolicum, and Cynomorium coccineum occur. 
“The elevated plateaux around the Koko Nor and upper 
Hoangho are either salt-marshes and very sparsely covered with 
such herbs as Nitraria, Kalidium, Polygonum Laxmannt, Orchis 
salina, Iris ensata, Pedicularis cheilanthifolia, Primula sibirvea, 
or expanses covered with Lastagrostis splendens, Stipa orientalis, 
and other grasses, or meadows in which grow Calimeris altaica, 
Thalictrum petaloideum, Oxytropis aciphylla, and a few Tibetau 
species, such as Hypecoum leptocarpum and Hymenolena sp., for 
example. Trees and the taller shrubs have withdrawn from the 
fierce winds either into the mountain-passes or to the deep pre- 
cipices and ravines of the loess, where open woods exist composed 
of Populus Przewalskii, with a trunk sometimes 70 ft. high and 
two feet thick ; Hippophaé, 40 ft. high and one foot thick; Adbves. 
100 ft. high and three to four feet thick; trees of Juniperus 
Pseudo-Sabina, and very frequently shrubs belonging to the 
genera Berberis, Sorbus, Cotoneaster, Lonicera, Rosa, Ribes, ete. 
“On the high plateau of Tibet there occur not a few Mongoliav 
or Siberian species, especially in the saline areas. 
