THE INDIGENOUS “RUBBER” TREES 
OF BRITISH GUIANA. 
By F. A. Stocxpatez,B.A., F.L.S., 
Assistant DrrEcTOR OF SCIENCE AND AGRICULTURE, 
AND GOVERNMENT BoTanist. 
In the earlier numbers of ‘ Timehri,’ Mr. Jenman gave accounts of some of the 
latex-producing trees of British Guiana. Since these articles were published 
further information has been obtained and as there have been during the past 
year frequent enquiries in regard to the indigenous “rubber’’ trees of the colony, 
it seems desirable that our knowledge of them at the present time should be plac- 
ed on record. There are still many details that are required, but if this brief 
survey, chiefly from a botanical standpoint, does no more than awaken a keener 
interest in a subject in which there are still many “ gaps” its object will have 
been attained. An exact botanical knowledge of the different species of Hevea 
found in the colony is yet required, while further information in regard to the 
yields and distribution of the different species is desired. Many details in 
regard to the different species of Sapium are still wanting, and data in regard 
to the products obtainable from the lesser known latex-producing plants are 
very scanty. 
Rubber of commercial value is obtained from different species of Sapium, 
but the products yielded by the indigenous Heveas have so far been found to 
have but a very low value on the market. Some samples have been valued at a 
price that might be considered commercially if the yields from the trees were 
satisfactory, but it is just here that fuller information is most desirable. 
Material for examination is being collected as opportunities offer, but much yet 
remains to be done 
Locat Heveas. 
The species of Hevea recorded from British Guiana are Hevea Spruceana, H. 
pauciflora and H. confusa. In the previous articles in ‘ Timehri, Mr. Jenman 
described what was supposed to be Hevea Spruceana and in reports to the Gov- 
ernment gives some account of its distribution and yields. From a large amount 
of herbarium material sent to the Royal Botanic Gardens, Kew, in 1899 and 
1900 by Mr. Jenman, there seemed to be some doubt as to whether Hevea 
Spruceana really existed in the co'ony and the authorities referred the material 
sent as H. Spruceana, to H. pauciflora and H. confusa. The only specimens of 
H. Spruceana, not referred to other species yet, in the British Guiana Herbarium 
were collected by Mr. Jenman on the Essequibo river in 1886. 
Hevea Spruceana is a Brazilian species, and is described as a tall tree with large 
smooth, distinctly petiolate, leaflets of a papery or subcoriacious character. The 
leaflets are ovate-lanceolate and generally of greatest breadth near their basal 
ends. The petioles have only two-glands at their apices. In this character H. 
Spruceana differs from the other species of Hevea of the colony, as they usually 
have three or four glands. The female flowers are few in number while the 
male flowers are very numerous and small. 
