I90 SOUTH AFRICAN FLOWERING PLANTS. 



allied to the Deadly Nightshade. But of all plants 

 the Potato is the most useful. Even this is not harm- 

 less in the^ green state ; and tubers should never be 

 allowed to be exposed to the sun when growing, for 

 that reason. It is a native of South America, and in 

 the wild state produces tubers about one inch in 

 diameter. The chief use of this vegetable is on 

 account of the large amount of starch which it contains, 

 some 15 per cent. Water amounts to about 75 per 

 cent., and the most nutritious (nitrogenous) ingredient 

 only 2 per cent. ; whereas this, which supplies muscle, 

 bone, and brain -forming matter, amounts to over 20 

 per cent, in beans, peas, and lentils of the leguminous 

 family. Hence potatoes are an excellent accompani- 

 ment to meat, but taken alone, would furnish a very 

 poor diet indeed. 



Sola'num. — There are thirty-three Cape species. 

 The illustration (Fig. 77) is that of B, ni'grum, a 

 common weed in English cultivated gardens, which is 

 found not only widely dispersed by man, but wild in the 

 most out-of-the-way places, as the Galapagos Islands,- 

 two hundred miles off the west coast of South America. 



The inflorescence has the peculiarity of rising mid- 

 way between the leaves on the stem. (1) is the corolla 

 laid open to show the adherent stamens ; the anthers, 

 (a), open by pores, as in Heaths. (2-I-) represents the 

 calyx and pistil only; (2-I-+) is a transverse section 

 of an ovary with the much-enlarged axile placentas 



