but on the banks of the river and creeks, a situation they 
seem to prefer, they are branched, much stouter and 
hardly erect, but lean out in the center, in the effort to 
steer clear of their close-growing neighbors. . . Septem- 
ber is the flowering season, and April and May is, I 
think, the fruiting season.” 
3. Notes on chemical analyses of Hevea rubber samples 
Hevea Benthamiana Mueller-Argoviensis in Lin- 
naea 34 (1865) 204. 
CoL_omsi1a: Comisaria del Amazonas, Rio Cotuhé, near its mouth, 
near Tarapacd, ““Small tree, basally swollen, tapering rapidly up- 
wards. Bark externally dark brown, smooth; internally red; thin, 
peeling easily from cambium. Latex white, abundant. Leaflets rec- 
linate. Flowers yellow, some bright red in lower half of calyx. Ser- 
inga chicote.”’ September 8, 1946, Richard Evans Schultes 8123,.—Rio 
Putumayo, Tarapacd. ‘‘Leaflets strongly reclinate. Trunk 65 feet 
tall; basally swollen, 17 inches in diameter, rapidly tapering upwards. 
Bark very smooth, 5 mm. thick, soft, externally dark brown, inter- 
nally reddish. Crown compact, heavy. Flowers yellow, reddish at 
base. Latex white, of medium thickness.’’ September 9, 1946, Rich- 
ard Evans Schultes 8125. Same locality and date, Schultes 8126, 8127. 
A sample of smoke-cured rubber taken from an estrada 
of trees at Rapidol, on the left bank of the Rio Putu- 
mayo at Tarapaca in Amazonian Colombia has been ana- 
lyzed by Mr. A. V. McMullan of the Division of Rubber 
Plant Investigations, Bureau of Plant Industry, Soils, 
and Agricultural Engineering, with the following re- 
sults: ‘Resins (acetone extract) 2.60% ; Rubber hydro- 
carbon (benzene extract) 92.99%; Insolubles 4.41% ; 
Comments on character of dried benzene extract : Tough, 
strong and hard, similar to brasilensis. 
In the short-lived exploitation of wild rubber in Am- 
azonian Colombia during the past war, rubber from the 
vicinity of Tarapacd was purchased by the Rubber De- 
velopment Corporation as the equivalent of ‘‘Up-River”™’ 
(a relatively high grade of Hevea brasihensis rubber). 
[ 39 | 
