BOTANY. 393 



As to the Flora, several of the Orders which occupy 

 a prominent place in the last-named Region are here very 

 sparingly represented ; the terrestrial Orchids of the tribe 

 Ophrydeae are to a great extent superseded by the epiphytic 

 Vandeae ; Rubiaceae take a prominent place, while Euphor- 

 biaceae follow closely behind in point of numbers. 



The Karroo Region occupies another somewhat 

 narrow strip north of the South-Western Region, and 

 thence along the west coast as far as the Orange River. 

 It is a vast shallow basin of considerable elevation, with a 

 climate of great dryness, and extremes of heat and cold. 

 Most of the rainfall is from summer thunderstorms, and 

 during periods of drought nothing can be imagined more 

 desolate and mournful than the appearance of the vegeta- 

 tion. Yet after copious rains all is soon changed as if by 

 magic ; the shrublets are covered with flowers ; green 

 leaves are produced from the apparently dead bushes ; 

 bulbous plants, which may not have flowered for years, 

 send up their scapes with incredible rapidity, and annual 

 flowering herbs and grasses are everywhere seen, where 

 all was previously dry and barren. 



The predominating feature of this Region is the large 

 proportion of succulent plants of various Orders in its 

 Flora, especially Crassulaceae and Ficoideae ; also the 

 prevalence of thorny plants. With the two preceding 

 Regions the Flora shows but weak affinities. From the 

 South- Western it differs in the complete absence of the 

 six most characteristic Orders of that Region ; Rutaceae, 

 Bruniaceae, Ericaceae, Proteaceae, Penaeaceae, and Restiaceae. 

 From the South-Eastern Region it is distinguished by 

 the abundance of Ficoidese and Crassulaceae, and the 

 scarcity of Leguminosae, Rubiaceae, Acanthaceae, and one 

 or two other Orders. From both it differs in the great 

 scarcity of Orchids. 



The Upper Region, or Region of Composites, is 

 a large tract north of the Karroo, the northern boundary 

 as yet not very clearly defined, but falling far short of the 

 Orange River, except in its north-eastern portion, where 



