MONGOLIA 67 



characterizes the semi-deserts of Nevada, Colorado, and 

 Arizona in western North America, as well as the circum- 

 desert belts of northern Africa. Depressions and dry 

 river-beds, where some ground water remains during the 

 greater part of the year, are marked by a taller and 

 thicker growth of grass ; a species that attains large 

 proportions in favourable situations is the kamish. 

 There are very few of those strange succulent, bulbous, 

 or tuberous water- storing plant-forms of the American 

 and African deserts: tree and bush vegetation is 

 represented by solitary small trees or occasional 

 thickets at the foot of a hill or in the dry bed of 

 a temporary river, where rhubarb may also be found 

 wild. These trees are held in great veneration by the 

 natives. The usual flora of small plants, which may 

 lie for years in the seed- stage and burst into an 

 ephemeral life only after the casual rains, is not lacking 

 in Mongolia ; in season, one-flowered tulips occasionally 

 adorn the ground with fragrant and beautiful carpets. 



The true steppe constitutes another belt outside those 

 just described. It extends in a narrow strip along the foot 

 of the mountains carpeting their foot-hills and penetra- 

 ting deep into their valleys. All but dry and apparently 

 dead in summer, it displays a beautiful mat of blooms in 

 spring. In this region, the oases are usually disposed in a 

 string along the marginal mountain-chains ; they develop 

 where the snow-fed rivers dry up or disappear in the 

 sand shortly after leaving the hills. To the north of 

 the desert, their vegetation is distinctly of the northern 

 type. They are recognized in the distance by screens 

 of gaunt poplars and willows, elms and ashes, all summer- 

 green trees with which we are familiar; and such 

 shrubs as dog-rose, bramble, raspberry, and honeysuckle 

 would remind us of home vegetation, while the tall 



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