196 Information respecting Botanical Travellers, 



ing as the moisture is more or less prevailing, or the thin stratum 

 of mould is mixed with sand, we may trace individuals of the ge- 

 nera Crotolaria*, Lisianthus, Coutoubea, Hibiscus, Shdtesia, Zornia, 

 Stylosanthes, Elephantopus, Mimosa, Eupatoriiim, Latreillea, Unxia, 

 Wulffia, Centrosema, Phaseolus, Indigofera, Tephrosia, Porophyllum, 

 Hyptis, Gerardia, Lippia, Crypto calyxf, Camara, Aegipliila, Amaso- 

 nia, Irlbachia, Bacopa, Buchnera, Beyrichia, &c. A few stunted trees 

 of the Curatella americana, the rough leaves of which are so useful 

 to the Indian for polishing his arrows and war clubs ; some MaU 

 pighiie, the bark of which the Brazilians use for tanning, are di- 

 spersed over the savannahs, and in consequence of their almost equal 

 size, do not contribute to lessen the monotonous aspect of these plains 

 — nor do they afford shade to the weary traveller, as their inconsider- 

 able size and thinly scattered foliage, does not lessen the effects of 

 the solar rays upon him, who should seek shelter under their branches. 

 Coppices of wood rise sometimes like oases out of these savannahs, 

 and are marked by trees of considerable size. On approaching such 

 a desirable refuge from the heat of the sun, the transition from the 

 vegetation of the savannah to that of the forest, is highly remark- 

 able. The solitary trees of the Curatella become more numerous ; 

 they are interspersed with arborescent shrubs, chiefly belonging to 

 the natural orders of Rubiacea and Composite, and it appears still 

 undecided, whether forest or savannah is to have the predominance. 

 We approach the wood, girt by species of the genera Helicteris, Mi- 

 mosa, Bauhinia, Apeiba, Solarium, &c., satisfied with but little nou- 

 rishment, and inured to the full action of the sun. In their vicinity 

 we may observe the Agave, and several erect and angular Cacti, some 

 of the latter in form of huge Candelabras, or overtopping in height 

 the surrounding trees J, perhaps adorned with flowers remarkable for 

 their beauty, — alas ! of short duration — or inviting by their purple- 

 coloured fruits. Divers species of Inga, several Cassiece, Combretacea, 

 LecythidecE, and MyrtacecB, distinguish the interior of the small forest, 

 which is seldom more than two miles in circumference. Occasionally 

 tracts of huge blocks of syenite traverse the savannalis, or shelves 

 of granite just rise above the earth, and extend to a considerable 



* For a detailed account of the plants collected during my expeditions in 

 the intei'ior of Guiana, see Enumeration of plants collected by Mr. Schom- 

 burgk in British Guiana, by George Bentham, Esq., Annals of Natural Hi- 

 story, Numbers VIll. XII. XIX. and XX. Mr. Bentham's kind intentions 

 are to continue their systematic description in future numbers, while divers 

 sets of these plants, of about 909 species each, remain to be disposed of. 



f Annals of Natural History, No. XII. p. 446. 



J I have observed in the vicinity of Pirara in one of these coppices a Ce- 

 reus, the height of which I estimated at from 50 to 60 feet. 



