Chap. IX] DESERTS 649 



woody, usually viscous or hairy ; the shrubs, averaging one to three meters in height, 

 are squarrose, scrubby, and thorny, and apparently dead owing to the exceedingly 

 small development of their foliage. With few exceptions the whole forms a mixture 

 of tall and short, oval, globose, elongated or otherwise shapen, dark, greyish or 

 yellowish green, loose (and then shadeless) or densely interwoven, thorny masses 

 or brush-like woody plants, on hard grey or reddish soil, formed of pebbles, gravel, 

 or sand, or on dunes, when not blown down with the shifting sand that the storms 

 constantly drive before them. It sometimes appears dense, sometimes with large 

 blanks. Here individuals are isolated, there in groups or struggling with one another 

 for existence, according as the meagre soil nourishes them and the subterranean 

 water sends up to them a supply of moisture. One kind of shrub grows vigorously 

 upward, with the appearance indeed of a stunted existence ; another creeps, a third 

 is pressed against the ground, a fourth contracted into a dwarfed condition, a fifth 

 grows in cushions, and so on. Most of the shrubs are densely, shortly, vertically, 

 and often crookedly branched, and rod-like, bushy, thorny, also gnarled or otherwise 

 malformed. Not unfrequently the older branches are found to be dead. Dark 

 brown, greyish or yellowish green, and usually rough, is the appearance of the 

 strongly suberized cortex ; in one plant it also exudes wax, in another it is provided 

 with resinous or gummy excretions. The leaves are usually tiny and caducous, 

 occasionally as in Fabiana Hieronymi, Niederln. they are scales, but in saline shrubs 

 they are fleshy, in other bushes leathery or hard and thorny, in others again they 

 are transformed entirely into thorns or prismatic needles, and, though in Mimoseae 

 and other families the leaves reappear periodically, they are absent in Monthea 

 aphylla, Cassia aphylla, and some other shrubs. Only a few of the flowers are 

 remarkable for beauty, scent, or size.' 



SELECT LITERATURE. 



1. Deserts of the Eastern Hemisphere. 



Bary, E. de. Ueber den Vegetationscharakter von Air. Zeitschr. d. Gesellschaft 



fur Erdkunde zu Berlin. Bd. XIII. 1S78. 

 Bolus, H. Sketch of the Flora of South Africa. The Official Handbook, Cape of 



Good Hope. 1886. 

 Brandis, D. Regen und Wald in Indien. Meteorol. Zeitschrift. 1887. 

 Bunge, A. v. Pflanzengeographische Betrachtungen iiber die Familie der Cheno- 



podiaceen. Mem. de l'Acad. imp. des sciences de St.-Petersbourg. Ser. 7. 



Tome XXVII. 1880. 

 Dove, K. Das Klima des aussertropischen Siidafrika. Gottingen, 1888. 

 Herder, F. v. See Krasnov. 

 Krasnov, A. Geobotanical Researches in the Kalmuk Steppe. Bulletin of the 



Russian Geographical Society. Vol. XXII. 1886. (In Russian.) Extended 



reference by F. von Herder in Engler's Jahrbiicher. Bd. X. 1889. Littera- 



turbericht, p. 53. 



