84 VEGETATION OF SOUTHERN NAMIB. 



One of the few larger species of the region is M. inonilijorme, 

 which reaches a height of two to three feet, and is mostly confined 

 to the sandy plains. In spring young shoots with the usual form 

 of sessile decussate, succulent leaves appear, but they soon shrivel 

 up, while their basis swells, forming a series of swollen joints, 

 which the name of the plant well describes. Similar in its 

 appearance to some species of Mesembrianthemiim is the widely 

 spread Augea capensis, w'ell known in some parts of the Karroo. 

 The leaves are so gorged with sap that each forms a cylindrical body 

 about an inch long, rounded off at both ends, but the juice here is 

 so saline, that not even a camel can eat the plant, although these 

 animals find the Salsola quite palatable. 



A conspicuous feature of this formation is the occurrence of 

 some GeraniaceaC; of which three are particularly common, viz. : 

 Pelargonium crassicaule, P. cortusifolium and Sarcocaulon Burmanni, 

 all three being clumsy shrublets with short and stout l)ranches 

 which remain leafless for at least nine months of the year, viz. : 

 from October to June. P. crassicaule is hardly ever more than 

 10 inches high and 10-15 inches in diameter, the branches being 

 as thick as one's thumb and quite smooth, and as they are nearly 

 black, the plant forms a conspicuous object on the bare rocks 

 during the greater part of the year. P. c or tii si folium is often 

 considerably larger, reaching two feet in height and diameter 

 and forming a very ornamental object when in full leaf and 

 flower. 



The Sarcocaulon differs from the pelargonia by possessing spines, 

 often one to two inches long, the specially modified pedicels of 

 former leaves. The plant produces two sets of leaves ; one kind, 

 sessile and tufted, appears every year early in spring on stem 

 and branches, the others, with long pedicels, are produced a little 

 later, on the growing points of the branches, provided that the 

 season has been favourable enough to induce further growth of 

 the plant. When the pedicels have become sufficiently stout 

 and long,- the blades drop, and the remaining, sharp-pointed spines 

 harden, their development showing that they are not merely 

 the remains of the leaves, but organs of special adaptation and 

 protection, the plant having devoted a considerable amount of 

 building material to their construction. In spring these Sar- 

 cocaulon plants, covered with bright green leaves, are quite a treat 

 to the eye, especially where they are numerous enough to influence 

 the colour of the landscape. Later on, in September or October, 

 the flowers appear and are often so numerous, that every plant 

 looks like a rose coloured patch on the otherwise bare ground.* 



Similar to the shrubby pelargonia are two or three species of 

 Othonna, among them 0. cacalioides, which in summer shows 

 only the bare carnose stems, but becomes covered with bright 

 leaves in spring. The alhagi-type of the North- African deserts is 

 represented by Parkinsonia africana, and several species of Leheckia, 

 among them L. multi flora, the latter producing white silvery 

 leaves in winter, but remaining almost bare in summer. 



* The plant differs from the typical S. Burmanni by having pink flowers. 



