152 XL. AMPELIDE^. 



distance of about 300 miles towards the interior of the continent, 

 increasing in the number of species and at the same time in the 

 number of incUviduals. The distribution is such that the fleshy- 

 species principally inhabit the littoral region, the climbing species 

 with glossy coriaceovis leaves predominate in the mountainous 

 region of the primitive forests, and the erect species affect the 

 highlands of the interior ; and this relation of the scandent 

 species to the erect species is so marked that there were found in 

 the mountainous region of primitive forest (1000 — 2400 ft. alt.), 

 amongst about twenty species, only a very few erect species ; 

 while on the plateau of Huilla, which rises far above 5000 ft., 

 though covered with forests and eminently adapted for climbing 

 plants, there occurred, amongst eight species, only two scandent 

 species. A humid atmosphere is favourable to the development 

 of Ampelidese, but principally of the scandent species ; there 

 occurred in the high mountainous tracts of the interior — as, for 

 instance, in the sandy forests around Pungo Andongo and in the 

 forests of Huilla, composed of species of Protea and Parinariuni — 

 chiefly erect species ; such not having been seen at all in the 

 littoral region, and very rarely in the high forest region. A con- 

 siderable number of species do not at all occur in the jungles on 

 the coast, but in rather dry sandy ground or on rocky cliffs, and 

 two species even on the most arid burning Gneiss -rocks or in loose 

 sands, as, for instance. Cissies ruhiginosa and C. jatrojohoides. In 

 all parts of West Tropical Africa, where woods of Proteacese 

 occurred, exclusively erect species were found (see Welwitsch, 

 Sert. Angol., p. 30). 



A second characteristic, which is represented in the geographical 

 distribution of the species of Cissus and allied genera in Angola, 

 is the pubescence and indumentum of the stems and leaves of these 

 genera ; while the species growing in the littoral region have 

 mostly light-green and not very hairy stems and leaves, the 

 species occurring in the region of the primitive forests are noted 

 for their dark-green, glossy, more or less coriaceous, and frequently 

 evergreen foliage, and neaily all the species of the highland region 

 of the interior show always a more or less dense pubescence or 

 even a tomentose indumentum on the stems and leaves, which, in 

 Cissus ruhiginosa Planch., a species occurring on the Gneiss-rocks 

 of Pungo Andongo, is formed into so dense a gold-tawny shining 

 velvet that the whole plant appears as if chiselled out of solid 

 copper, and deserves to rank amongst the most beautiful plants of 

 Angola. 



C. jatrojihoides, a species without tendrils, with a singular habit, 

 and with brilliant scarlet flowers, is peculiar to the Ambaca 

 district. 



The Ampelidese luxuriate with the greatest splendour in the 

 primitive forests of Golungo Alto and Cazengo, but the greatest 

 variety of forms is apparent in Pungo Andongo. A foremost 

 rank must be assigned to this family as ornaments of the steppes, 

 thickets, and forests, both to the scandent and to the erect species, 



