1953] 



VEGETATION OF NY AS ALAND 



183 



season burning the grasslands thus established. The present Apoka of the 

 plateau are the descendants of a remaining group of a much larger population 

 which in the 19th century was driven onto the high country by the marauding 

 Angoni and settled there for a time. 



The prevailing grasses of the plateau had shed their seeds and were not 

 in condition to collect at the time of my visit. Recognizable, however, as 

 the most important species, was Exotheca abyssinica (Hochst. ex A. Rich.) 

 Anderss., also the dominant grass of the escarpment above Nchena-chena. A good 

 representation of shrubs and herbs occurred near forest borders, but such plants 

 on the great open grasslands were remarkably though not unexpectedly few in 

 species, and migration mainly from lower altitudes seemed indicated. The 

 commoner herbs included * Helichrysum 17218, H. fruticosum (Forsk.) Vatke, 

 H. kirkii, Osteospermum monocepbalum (Oliv. & Hiern) Norlindh., Gerbera abys- 

 sinica Sch. Bip., Caucalis pedunculata Bak. f., Lotus aff. oehleri Harms, Swertia 

 johnsoni N. E. Br., Sebaea grandi flora Schinz, and Buchnera crassifolia Engl. 

 Shrubs included the very small heaths Blaeria patula (Fngl.) Engl, and B. 

 kiwuensis Engl., Anthospermum usambarense K. Schum., Protea kingaensis Engl., 

 and Selago thomsoni Rolfe. The grassy bogs were often edged with bracken 

 [Pteridium aquilinum (L.) Kuhn] killed back as if by frost, and in them Blechnum 

 tabulare (Thbg. ) Kuhn, of almost tree-fern stature, grew in abundance. Also in- 

 habiting bogs was a smallish species of the giant mountain lobelias (L. ? mild- 

 braedtii Engl.) growing higher than a man but, unfortunately, past flowering. 



The primary montane forest survived in greatest bulk on steep slopes close 

 below the rim of the plateau. Isolated relic patches occurred on some plateau 

 hilltops near the edge of the escarpment. Under presumably drier or less 

 misty conditions farther back on the plateau, the forest relics were in hollows 

 which afforded a certain amount of protection from winds which would intensify 

 the impact of grassfires. The most distant relic examined was a patch of a few 

 acres dominated by Juniperus procera Hochst., four hours walking distance west- 

 erly from camp, at an altitude of about 7,200 feet in the valley of the Uyaghaya 

 stream. Here at the southernmost known limit of its range, the juniper attained 

 a height of 100 feet or more and a trunk diameter of 4 or 5 feet. The Forestry 

 Department maintained a firebreak around the fragment of undisturbed forest and 

 nearby clumps and scattered trees of the species, left by fires, and saved from 

 destruction by Mission timbercutters who had come to this remote place to pitsaw 

 the trees for dieir fragrant, cedar-like wood. 



Junipers were not seen elsewhere on the plateau. In the primary forests 

 under the plateau rim, Podocarpus mil anji anus Rendle provided a plenti- 

 ful coniferous element, and Hagenia abyssinica (Bruce) J. F. Gmel., Macaranga 

 17294, Kiggelaria africana L., and Royena whyteana Hiern were other common 

 components. About 25 to 50 feet tall, these forests were plentifully mossed. 

 Undergrowth was predominantly woody; sparse under dense shade, abundant under 

 broken canopy and there even luxuriant with the entry of shrubs such as Piper 

 capense L. f. and Plectranthus albo-violaceus Giirke, and the tree-fern Cyatbea 

 17209. A sparse flora of vascular epiphytes included Peperomia retusa (L. f.) 

 A. Dietr., P. goetzeana Engl., Scbefflera polysciadia Harms as a large shrub, and 

 among ferns Adiantum poiretii Wikstr. and Hymenopbyllum 17260. 



A limited amount of forest regeneration was taking place on the plateau. 

 Three species of small trees, Philippia benguelensis (Engl.) Welw., Myrica 17221, 

 and Agauria salicifolia (Comm.) Hook, f., formed patches of more or less open 

 second growth forest or grew scattered in a sort of open woodland. These de- 



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