178 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VoL 8, No, 3 



half that height. A remarkable thing, this browsing by bushbuck. The bitten- 

 off undergrowth sent out side shoots which in turn were cropped back. The result 

 was a stand as even, as dense, and as severely trimmed as a well kept tea planta- 

 tion, with thick mossy tree trunks rising out of it — all in the heavy shade of the 

 forest canopy. 



Moist openings in the forest had their own complement of light-requiring 

 plants, most of them also found on banks of forest streams, for example, the 

 scrambling herbs Caucalis incognita Norman and Hypoestes triflora (Forsk.) 

 Roem. & Schult., the grasses Panicum monticola Hook. f. and * Eragrostis phaeantha 

 C. E. Hubb., and pinkish-flowered Impatiens shirensis Bak. f. growing 6 feet tall. 

 Down in the Luchenya Gorge, the stream side trees were shaggy with mosses and 

 crowded with ferns. The yellowish culms of a bamboo (Arundinaria alpina K. 

 Schum.) arched out over the water, and an opulence that only tree-ferns can give 

 was contributed by an abundance of Cyathea 16675, thick stemmed and up to 25 

 feet tall, and smaller C. 16600. 



On short acquaintance, the forest regenerative growths developed after dis- 

 turbance, as by fire and landslips, were not readily separable as a community 

 from border shrubberies which formed a narrow ecotone between primary forest 

 and grassland. Both communities made very dense growths which screened the 

 forest interior from wind, filtered out light, and no doubt played an important part 

 in protecting the forest from grassfires. Taken together, they contained many 

 colorful plants in a rich assemblage of species. Among common shrubs or small 

 trees were Agauria salicifolia, Philippia benguelensis, P. nyassana Aim & Fries, 

 Erica jobnstoniana Britt. and other Ericaceae; Vaccinium africanum Britt., 

 Hypericum lanceolatum Lam., Cliffortia nitidula (Engl.) R. E. & Th. Fries, 

 Anthospermum welwitschii Hiern, Coreopsis pinnatipartita O. Hoffm., Halleria 

 elliptica Thunb., Buddleja salviifolia Lam., and Dissotis jobnstoniana Bak. f.; 

 and in the Luguminosae, showy yellow- flowered Aescbynomene megalophylla 

 Harms and Smithia scaberrima Taub., and purple-flowered "Tepbrosia wbyteana 

 Bak. f. Plentiful as scrambling plants were Rubus ellipticus Sm. and herbaceous 

 Cineraria buchananii S. Moore. 



The grasslands comprised two major communities, one occupying de- 

 forested areas, the other generally at higher levels on the mountain and ap- 

 parently a primary condition. The rolling treeless ridges of Luchenya Plateau, 

 perhaps 10 square miles in area, offered a good example of the first type. The 

 soil was generally a shallow loam underlain by reddish bauxitic clay. When 

 exposed, as on paths, the bauxite ore formed clinker-like bodies that crunched 

 under 3ne's feet and were hard on boots. With the exception of Loudetia simplex 

 (Nees) C. E. Hubb., the predominant species, and Exotbeca abyssinica (Hochst. 

 ex H. Rich.) Anderss., the few grasses of a bunched, rather dense cover, about 

 18 inches high, were past seeding. Colonization from the lower mountain slopes 

 was indicated by the Loudetia and the Exotbeca, grasses of the Brachystegia 

 woodlands. There were no true grassland shrubs, and apart from several Gladiolus 

 species, in seed, about the only native herbs in evidence were showy yellow- 

 flowered Helicbrysum buchanani Engl., H. nitens Oliv. & Hiern, and H. lastii 

 Engl. Foxgloves (Digitalis), originally planted along paths, apparently had become 

 naturalized. 



The grasslands regarded as primary lay chiefly above 6,500 feet, at levels 

 frequently shrouded in mist when the lower levels were clear. They were dom- 

 inated by one or more coarse tussock-forming species, sterile when we saw 

 them. Much of the tussock-grass country is rocky and craggy and broken by bare 

 rock slopes often wet with seepage water. Hollows contain a black organic soil, 



