81 



ORDER CVI. APOCYNACEiE. 



A large family oi plants found chiefly in warm countries, though 

 many of them also inhabit temperate regions. Most, but not all of 

 the species, possess a milky juice which is sometimes purgative, 

 laxative, or febrifugal, and sometimes very poisonous. The seeds of 

 Gerhera Tang km, the " Ordeal tree " of Madagascar, though not much 

 larger than an almond, are said each to contain sufficient poison to 

 kill twentv men. Fortunately the plant rarely bears seed in the 

 Durban Botanic Gardens. From several species india rubber is 

 obtained, the kind which is largely exported from the East coast of 

 Africa being chiefly obtained from different species of Landolphia. 

 Of our indigenous species perhaps the best known and the most 

 valuable is Carissa grandiflora, the " Amatungulu." Carissa acuminata 

 also bears an eatable fruit, and is known as the small Amatungulu. 

 Acokanfhzra venenata is one of the plants from which the Bushmen 

 in old days extracted the poison for tipping their arrows, and most 

 likelv AcoJcanthera spectabilis has the same poisonous properties. The 

 bark of Uauwolfia natalensis is used medicinally by the natives. One 

 or more species* of Strophanthus were used by the natives of Central 

 Africa as arrow poison, and the seeds of these species are now used 

 medicinally in Europe. The properties of our native species are as 

 yet unknown. 



Number of species about 900. 



(Ex. Amatungulu; Periwinkle, Etc.) 



Corolla lobes overlapping to the left, rarely to the 



right. Fruit baccate, drupaceous or dry. J 



Corolla lobes overlapping to the left, rarely to the 



right. Carpels 2, free or united at base. ^ 



Corolla lobes overlaf)ping to the right, rarely to 



the left Fruit follicular, seeds comose. ^ 



1 Shrubs with forked or thrice-forked spines. Carissa. 

 1 Unarmed shrubs, fruit a berry. Disk 0. A cokanthera. 



1 „ „ „ ,, „ cup-like. Rauwolfia. 



1 Small undershrub, fruit a follicle, seeds 



small. LOCHNERA. 



2 Sepals almost or quite free. Tabern^ Montana. 



2 Sepals united into a tubular or sub-campanul ate 



tube, circumscissile or splitting. VoacaNGA. 



3 Corolla lobes long-tailed with paired appen- 

 dages between the lobes. Strophanthus. 

 3 Corolla lobes short, with 5 deltoid-accuminate 



scales in the throat. Onoinotis. 



3 Corolla lobes short with 5 oblong-bilobed 



scales in throat, Wrightia. 



