trations are reported in the areas around Maroa, San Carlos, the 
Desecho de San Miguel (Casiquiare) and the Cano de Guami (Rio 
Negro near Santa Rosa de Amanadona). 
Some of the men who worked rubber 1900-1914, said they ex- 
ploited Micrandra. Trees felled and ring-tapped every 3 ft. Latex 
collected as tree scrap. After 2 to 3 weeks, when the leaves were 
wilted, trees ring-tapped again at 2 to 3 inch intervals and the latex 
collected in gourdes of leaves. A tree 3 ft. in diam. would give about 
| gal. latex. Fairly stable. Coagulate in 5 to 10 hours. 
Various tapping tests tried mostly with low yields. In a few cases 
fair yields were obtained. One tree 24” DBH gave | 1/4 quarts latex 
at one tapping. This tree was just beginning to bud and other trees 
that gave good yields were just starting to grow. 
The latex coagulates rapidly on the addition of water. 
A native said that her father collected Micrandra rubber and 
always found a large lump of rubber at the base of the trees. Used a 
sharp stick to probe for the rubber. The lumps weighed 5 or 6 kg. 
each. 
Average yield about 150 gms. air dry scrap of lump per tree per 
day. An expert tapper with climbing equipment can tap about 10 
trees per day. 
It is interesting to note that the first of these reports does not 
mention exploitation but that the second maintains that Micran- 
dra was exploited from 1900 to 1914. The trees were felled, 
ringed and the latex allowed to coagulate as scrap on the trees. 
This was undoubtedly the so-called Caura rubber formerly 
exported from the Orinoco basin of Venezuela. Neither of these 
reports indicates that Micrandra was in production in the 1940’s, 
and I have been unable to find any data which would support 
the belief that these trees were ever used to any extent during the 
recent war-shortage of rubber. 
Unfortunately, I have been unable to find voucher herbarium 
specimens upon which these foregoing reports might have been 
based. In the Venezuelan region concerned two closely related 
species are known to occur: Micrandra minor and M. siphoni- 
oldes. 
Allen, who carried out surveys for the Rubber Reserve Corpo- 
ration in Colombia at the same time, has recorded on voucher 
specimens exceedingly interesting notes concerning the type of 
rubber and its possible exploitation. All of his observations on 
Micrandra were made amongst the Tukano Indians on the Rio 
Papuri, an affluent of the Rio Vaupes, which forms part of the 
boundary between Brazil and Colombia. Of Micrandra minor, 
98 
