i86 SOUTH AFRICAN FLOWERING PLANTS. 



Floioers — Sepals, 5, persistent ; corolla, regular, 

 petals coherent, and withering on ; stamens adherent 

 to corolla ; ovary, 1-celled with opposite placentas. 



Fruit — Capsule. 



Convolvulaceae. 



The Convolvulus Family. 



This family is largely made up of climbing herbs. 

 There are about 800 species of 32 genera in 5 tribes. In 

 South Africa there are 11 genera. 



Some have a milky juice, and one yields a drug 

 known as " Jalap," as it comes from the town Xalapa in 

 Mexico. Another from South Europe is also medicinal 

 under the name of " Scammony." 



The sweet potato is the underground stem of a 

 species of Batatas, a name which became corrupted into 

 " potato " in the sixteenth century. The Natal cotton- 

 plant is another species of this genus, the seeds being 

 covered with long hairs, as the seeds of the true cotton- 

 plant {Gossyjo'lum) are. Most of the members of this 

 family climb by their stems, but some species living 

 out in hot desert-land are little woody, shrub-like plants, 

 without any climbing powers at all, while closely allied 

 ones may be found climbing in forests, etc. This has 

 suggested a probable origin of this habit. Where plants 

 grow under shade they get " drawn," as gardeners say ; 



