PRESIDENT S ADDRESS. ^( 



The remnants of a larger forest, which was apparently 

 Bimilar in composition to that of the Knysna, still exist on the 

 rocky slopes of the Langeberg near Swellendam. 



On the west coast the ClanwilHam Cedars [Widdringionia 

 juniperoides) occur on the Cedar Berg Mountains. These 

 mountains also produce the well-known Buchu {Barosma 

 betulina) of commerce. 



Among the poisonous plants in this region may be mentioned 

 Lessertia annularis, the Klimop {Cynanchum capense), the 

 Chinkerchee {Omitliogalion ili ijrsoidcs), various species of blue and 

 yellow tulps (Moraca and Hoincrla spp.),. and several introduced 

 plants. One of these, Datura stramonium, which has established 

 itself as a weed almost all over the country, is a valuable drug 

 plant. 



Elytropappus rhinoccrotis is a very common and usurping 

 weed of the grazing veld, its inroads being largely due to 

 overstocking and burning the veld. 



16.— The Kapjioo {Plates XX, XXI ). 



The Karroo embraces the low-lying stretch of country which 

 lies immediately south of the southern portion of the Great 

 Escarpment. 



The valleys of the Sundays Eiver in the east and the 

 Olifants Eiver on the west may be taken as approximately its 

 eastern and western limits. To the south it is intersected and 

 bounded by the Cape Ranges. It varies considerably in altitude 

 from 1,000 ft. in the central portion to 4,000 ft. above sea level 

 in the west. 



The average annual rainfall also varies from under 5 inches 

 in the west to 15 inches in the central and eastern portions. In 

 the west the greater part of the rain falls during the winter 

 months, whereas the summer rainfall increases from the central 

 portion eastwards. 



The Karroo is a country of shallow soils and rock-strewn 

 surfaces, consequently, when rain does occur, the ruu-nff is 

 extremely rapid. 



The country is devoid of trees except along the dry river 

 courses, where a few t]iorn trees and kameelhooms usually occur. 

 Grass is also almost entirely absent. 



The vegetation is largely composed of succulents, xerophytic 

 shrubs and shrublets. 



The Karroo may be divided into four main regions: (1) The 

 Great Karroo or Central Karroo; (2) The Western or Ceres Karroo: 

 (3) The Little Karroo, and (4) The Eobertson Karroo. 



The Great or Central Karroo includes the Ghoup, 

 Moordenaars Karroo, and the Eastern Karroo. 



The vegetation in the Ghoup is composed mainly of small 

 bushes and shrublets, amongst which Rhigozuni obovafum usually 

 dominates, with it are commonly associated Lycium arenicolum , 

 several species of Pelargoyiiuvi {P. munitum., P. carnosuyyt^ and 

 P. crithmifolium) and the Bushman's Candle (Sarcocaulon 

 Burmanni). The Karroo bush, Pentzia virgata, and the Kraal 

 Bosch (Galenia africana) are also often dominant over large areas. 



