260 MR. E. F. IM THURN ON THE PLANTS 



way by plants characteristic of that mountain, such as Marcetia taxifolia [No. 68], 

 Cassia Boraima, Benth. [No. 71], Dimorphandra macrostachya, Benth. [No. 39], Meiss- 

 ueria microlicioides, Naud. [No. 174], Galea ternifolia, Oliv. [No. 27]. To rue the most 

 interesting plant on this river was a very beautiful little slipper-orchid {Selenipedivm 

 Klotzschianum, Beichb. f. [No. 31]), which grew in the moist gravel of the river-bed, where 

 the plant must frequently be under water. This plant we also found in great abundance 

 on an island in the Cotinga river, on another in the Roraima river, and on a small creek, 

 called Aroie, a tributary of the Cotinga. Naturally the Arapoo river, as are its fellows 

 flowing from Boraima, is an artery allowing of the dissemination of the plants of that 

 mountain. 



At last we reached the Kookenaam river, at the village of Teroota, at the base, that 

 is, of Roraima. Even beyond the bed of the river, for some distance up the slope 

 of the mountain, the tract of ordinary savannah vegetation still continues, its charac- 

 teristic plants ever becoming more and more mingled with plants belonging to the 

 Boraima flora, till the very distinctly marked zone of strictly Boraima vegetation is 

 reached. 



The course of the Kookenaam river, where it flows through the tract of neutral 

 vegetation — vegetation, that is, not yet deprived of ordinary savannah plants, and not 

 yet composed exclusively of Boraima plants — is, as was the course of the Arapoo river 

 already described, very well defined by the large number of Boraima plants clustering 

 on its banks. Among these may be mentioned various shrubs, Ilex Macoucoua, Pers. 

 [No. 75], Dipteryx reticulata, Benth. ? [No. 73], Myrcia Roraima, Oliv. [No. 74], and 

 another species close to M. Kegeliana, Berg [No. 82]) which in places fringe the banks of 

 this stream, and are also characteristic of the upper, proper flora of the mountains. 

 Along the banks of this river, after its emergence from the mountain, grows in the peaty 

 soil at the water's edge a very beautiful and sweet-scented white orchid (Ayanisia alba, 

 Bidley [No. 360]), and on the more rocky parts of the bank a very remarkable red 

 passion-flower [No. 84], with panicles of many pendent flowers, each panicle having the 

 appearance — the facies, to use that ugly but convenient term again — of a spray of fuchsia- 

 blossom * It was here, too, in the deep cuttings made by the river and half filled up 

 with huge blocks of stone which are now overgrown with gnarled trees and shrubs, that 

 one of the most famous of all Roraima plants grows — Cat t ley a Laiorenceana, Reichb. f. 

 [No. 80]. 



This Cattleya is doubtless the one collected by the Schomburgk brothers, and enumerated 

 by Richard Schomburgk as C. pumila; for it appears to be the only representative of this 

 genus occurring on this side, at least, of Roraima, and this was the only side visited by 

 the Schomburgks. It grows apparently not high up on the mountain, but on the gnarled 

 tree-trunks, close to the water, in the clefts through which the Kookenaam and some of 

 its small tributary streams flow, at a height of about 3700 to 4000 feet above the sea. At 

 the time of our visit, Mr. Siedel, an orchid collector, having set the natives to work 

 to collect this plant for him, I have seen ten or twelve of these people come into 



* This passion-flower is well figured in Schomlmrgk's drawings, of which mention has already been made. 



