VEGETATION OF SOUTHERN" NAMIB. 8l 



according to the nature of the ground, viz. : the seashore.'" the 

 sandy ])lains, the rockv hihs and the gravel-covered flats oT the 

 rising plains Ijeyond the coastbelt. ■ r j I 



The Seashore.— Ma.ny parts of the coast are rocky, and conse- 

 quently do not show much difference in their vegetation from 

 higher parts ; others are occu]Med by sand dunes and are then 

 devoid of all vegetation, on account of the ever-shifting nature 

 of the sand. Around the lagoons, however, and at other shallow 

 portions of the shore a typical vegetation has established itself. 

 This is naturally very siniilar to that of the coast of other coun- 

 tries situated un.der similar conditions of climate. The three 

 principal plants are Salicornia natalensis. Bassia diffusa and a 

 coarse grass, all three so well adapted to saltwater that they do 

 not suffer by being submerged at high tide. 



The sandv tracts and dunes. — A little further away from the 

 sea the vegetation of the sandy tracts becomes more varied, and 

 as everywhere, even 20 or more miles inland, the sand is charged 

 with a considerable amount of saline constituents, the vegetation 

 of the sandy plains and slopes is fairly uniform, except where under- 

 ground water courses favour its development. 



The most common and most conspicuous plant is Salsola Zeyh.vi, 

 a low, compact shrub, which occasionally reaches a height of three 

 feet or more. Unlike its near ally, Salsola aphylla, the common 

 " ganna " of the Karroo river beds, which has glaucous leaves, 

 it is white-woolly and, even after rains, of grey appearance. It 

 is of considerable economic importance, for it is readily eaten by 

 the camels used for transport purposes and military expeditions, 

 and in many parts no other fuel than this shrub is obtainal)le. 

 Similar in size, but less common, is Lyciimi tetrayidrnm, which bears 

 bright green leaves in spring and numerous pale blue flowers. 

 Where the sand is deeper and not too readily shifted by the wind, 

 two widely-spread dune-grasses form isolated groups or even 

 closed patches, viz. : Eragrostis spinosa, the vogelstruis-grass of 

 the Cape colonist, and Ammophila arenaria. the Marram-grass of 

 the Australian coast, which, however, occurs in many other parts 

 of the world. Equallv common are Statice scabra and Mesein- 

 hrianthetnuni Marlothii. which, in favourable localities, e.g.. in 

 valleys that gently descend towards the coast and consequently 

 possess a certain amount of underground drainage, form lumps 

 up to two feet in diameter and, assisted by the accumulating sand, 

 one to two feet high. The Mesembriantheiniim is as common on 

 the rocks as on the sand, and one may look upon it as one of the 

 dominating and most specific plants of the Namib. In fact there 

 are wide stretches of hilly country South of Angra Pequena which 

 at first sight do not appear to possess any other vegetation. Fre- 

 quent, but not quite as common, are two snow white composites, 

 viz. : Dicoma tomentosa and Eremothamnus Marlothianus. which 

 form lumps up to a foot in height and diameter. 



The rocky hills. — Much more varied is the vegetation of the hills, 

 for many plants, which cannot thrive in the shifting sand, find 

 here suitable resting places, and although the vegetation nowhere 

 becomes closed, it is not rarely sufficientlv powerful to influence 



