171) OUTLINE OF PLANT GEOGRAPHY 



of this the land is either a grassy savanna with scattered trees, 

 or a steppe covered with dry thorny, and in winter, leafless scrub; 

 or sometimes, low open forest. 



Rising to the east and north are the highlands of Abyssinia, 

 1,800-2,500 metres in height, and consequently temperate in 

 climate. The lower portions of the western slopes, rising from 

 the Nile steppe, have dry open woods with tall grasses between 

 the trees, one of the commonest trees being the tamarind (Tama- 

 rind us Indicus), which in general appearance is not unlike the 

 American honey-locust (Gleditschia). Acacias of several species, 

 figs, including the sycamore fig (Ficus Sycamora) and a variety 

 of other trees and shrubs occur. Most of these shed their leaves 

 in the dry season, and often flower before the new foliage appears, 

 very much as do so many trees of northern climates. 



In the highlands there is no marked dry season, and the dif- 

 ferences in the vegetation are due largely to soil and exposure. 

 Where volcanic soils occur, there is a luxuriant evergreen forest 

 in which species of Ficus are conspicuous, and in general the trees 

 and shrubs are related to those of the drier lowlands. A date- 

 palm (Phoenix reclinata) is common, and among the character- 

 istic genera, are the following: Rhus, Pittosporum, Catha, Spar- 

 mannia, Dombeya, Croton, Acacia. 



The more luxuriant vegetation of these moister uplands is also 

 indicated by the increasing number of climbing plants, e. g., Aspar- 

 agus, Dioscorea, Clematis, Rubus, Phaseolus, Convolvulus, etc. 



As in other tropical high mountains, there is a large floral 

 element related to that of the temperate zone. In the Abyssinian 

 highlands one meets with many species of such familiar genera 

 as Gladiolus, Geranium, Pelargonium, Polygala, Hypericum, 

 Primula, Campanula, Dianthus, Lobelia, and many others, 

 especially members of the families Labiatae, Scrophulariaceae 

 and Solanaceae. 



Some of these are closely related to, or even identical with 

 European species, but many are unmistakably allied to species 

 of the Cape region of Africa. In the latter category are many 

 beautiful Iridaceae, e. g., Gladiolus, Moraea, Acidanthera; also 

 many ground orchids (Habenaria, Plantanthera, Satyrium, Disa); 

 Haemanthus, Crinum, Aloe, Mesembryanthemum, Protea, Ger- 

 bera, etc., are also characteristic. 



