Flora O rial fa lis 123 



much the richest and most varied in all the Orient. 2. Aralo-cas- 

 pian sub-region. Distinct from the last by its lower altitude and 

 less undulated surface. It includes the deserts of Tartary, the east 

 of Persia, and west of Afifghanistan. The winter is very cold in the 

 northern parts, the summer very dry, the rains of autumn and 

 spring fewer and more irregular than in the last sub-region. During . 

 the spring these solitudes are overspread by a number of small 

 plants, principally annuals, of very different families ; most of them 

 have an extensive area, and grow also on the Siberian steppes, of 

 which this region is the continuation. There are no trees except 

 in the cultivated oases, and a few poplars and willows along the 

 streams. The perennial plants which occur are usually more local 

 than the annual species, and there are a few shrubby genera not 

 met with elsewhere in the East or at all, of which Sophora, Ammoden- 

 dron, Eremosparton, Atraphaxis, Calligonum, Lycium, and Ephedra, 

 are examples. The salt plains occupy here a much greater space 

 than in the last sub-region, covered with Salsolacese and Zygo- 

 phyllese, and bushes of Tamarix, Haloxylon, and Nitraria. 

 3. Mesopotamian sub-region. Vast plains of alluvium, and the 

 deserts of the valleys of the Tigris and Euphrates. As on the pre- 

 ceding sub-region, the altitude above sea level is small, the summers 

 burning and prolonged, but the rains are more abundant, and the 

 winter much less rigorous. In the west and north the Flora re- 

 sembles that of the plateaux, but southward there are immense 

 plains covered at the beginning of summer with great Cruciferge, 

 Umbelliferse, and Cynareas. All the fruit trees except the orange 

 are known only in a cultivated state in a few favoured oases ; and 

 for this the winter is a little too cold and the summer too warm 

 and too dry. 



4. The Date Region. — This is characterised by irregular and 

 unfrequent rain in autumn and winter, which is quite absent from 

 the southern and lower parts of the region; the summer is burning, 

 the winter mild, but in the north, as at Bagdad for example, there 

 are occasional frosts. This includes Egypt, the north of Arabia, 

 and the shores of Persia and Beloochistan. The most remarkable 

 character of its Flora, consists in the presence of a number of 

 plants and shrubs of which we find the genera, and often the 

 species, to stretch through the desert tract from Scinde to 

 Senegambia. The date is a characteristic tree, spread through all 

 Egypt, mounting the valley of Euphrates to Bagdad, extending in 

 Persia to the thirty-third parallel of latitude, and in Beloochistan, 



