240 EAST AFRICAN FLORA AND FAUNA part in 



The application of this simple explanation to the anomalies 

 in the internal distribution of plants and animals in Africa 

 seemed prohibited by the general assumption that this continent 

 had always maintained its present form. Moreover, this ex- 

 planation does not fully account for the distribution of some 

 groups in small local patches ; and as soon as the scientific 

 exploration of Equatorial Africa began, numerous small outliers 

 belonging to one province were found to occur in the middle 

 of others. 



Thus, when Baron von der Decken returned from his 

 memorable expedition to Kilima Njaro in 1862, he brought 

 back with him a collection of plants, many of which were 

 determined by Ascherson to be species previously known from 

 the mountains of Abyssinia, such as Helichrysuni abyssinicum, 

 Sch. Bip., SpilantJies abyssmica^ Sch. Bip., and Achyrocline 

 Hochstetteri, Sch. Bip. Others, such as the tree lobelias 

 {Tupd), are allied to those of the same region, and others 

 belonging to genera such as the Wormwood {Artemisia) are 

 typical of the north temperate zone. During New's daring 

 visit to Kilima Njaro in 1871 he obtained specimens of twenty 

 plants, which enabled Sir Joseph Hooker and Professor Oliver 

 to add the Bartsia to the list of northern genera growing on 

 the mountain. The later collections of Teleki, Johnston, and 

 Volkens have fully confirmed the fact of a flora existing on the 

 higher part of this mountain, unlike that of the surrounding 

 lowlands, and allied with those of the mountains of Abyssinia 

 and the Cameroons, and to a less extent with those of the Cape 

 and the Mediterranean basin. 



The most striking of these plants was a giant groundsel, 

 which was first discovered on Kilima Njaro by Mr. H. H. 

 Johnston, after whom it was named Senecio JoJinstoni. This 

 plant, though belonging to the same genus as our English 

 groundsels and ragworts, grows as a tree from 20 to 30 feet in 

 height, resembling members of this genus previously known 

 from the mountains of Abyssinia and the Cameroons. 



In some photographs taken by Gedge at a corresponding 

 elevation on Mount Elgon, similar arborescent groundsels form 

 a conspicuous feature in the scenery. Count Teleki observed 

 another species on Kenya, and a view published by Stuhlmann 

 demonstrated the existence of a similar form on Ruwenzori. 



