Chap. Ill] MOUNTAIN REGIONS IN THE TROPICS 



74i 



With increasing altitude the tufts of grass become scantier. There are islands of 

 dense shrubs barely one meter high, which have a dark tone relieved by the white 

 flower-heads of Protea kilimandscharica (Fig. 437). At 3,600 meters, on the slopes of 

 lava and talus that are strewn with large blocks, there appears a loose stunted shrub- 

 formation, which Volkens has named Ericinella-formation, after the dominant species 

 Ericinella Mannii (Fig. 438, 3-5). At 3,600 meters a new shrub, Euryops dacrydioides 

 (Pig- 438, 1, 2), appears, and gradually becoming dominant, extends to above 4,000 

 meters. The character of the ground becomes more and more desert-like. 



' For a long time the vegetation has ceased to 

 be continuous even in patches. Above 4,200 meters 

 one must often take one or more steps to pass 

 from a clump of grass, scarcely a span in height, to 

 other flowering representatives of the vegetable 

 kingdom, for they are scattered in tiny tufts 

 over the stony or sandy tracts. Finally, at 4,500 

 meters we have reached the last outposts, all 

 isolated plants, forming little cushions under the 

 shelter of stones. There are still two grasses, 

 Koeleria cristata and Danthonia trisetoides, six 

 Compositae, Helichrysum Newii and H. frutico- 

 sum, Senecio Telekii and S. Meyeri Johannis, 

 Dianthoseris Schimperi, Carduus leptacanthus, 

 and a cruciferous plant, Arabis albida. Beyond 

 this, wherever the ground is dry, only lichens 

 and mosses prevail.' 



This desert is not without oases, small depres- 

 sions, in which rain or melted snow collects and 

 which are covered with a continuous carpet of 

 vegetation (Cyperaceae, Subularia monticola, Erio- 

 caulon Volkensii, Crassula Vaillantii). The last 

 oasis of this kind was seen by Volkens at 4,500 

 meters, but they may extend to 5,000 meters 

 according to Hans Meyer. 



Ravines longer retain a somewhat richer vege- 

 tation. The last stunted Erica-trees disappear from 

 them at 2,900 meters ; and are replaced by a new 

 characteristic plant of very peculiar habit, the ar- 

 boreous Senecio Johnstonii, with a spongy, simple 

 or forked stem, the top of which bears a rosette 



of leaves as long as one's arm, and a dense inflorescence a meter in length (Fig. 435). 

 Senecio Johnstonii bears the least resemblance to the alpine habit in this region. 

 It is remarkable, however, that plants of similar habit are also found on tropical high 

 mountains elsewhere. For the Vellozieae of Brazil are similar, and so to some 

 extent are species of Espeletia in the Cordilleras of Venezuela, regarding which 

 more detailed information is given further on '. In other respects the impress of 



1 See p. 743. 



Fig. 437. Alpine flora of Kiliman- 

 jaro. Protea kilimandscharica, Engl. 

 Half natural size. From a specimen 

 collected by Volkens, in the Berlin Her- 

 barium. 



