dent who is limited to herbarium material. Such field 
characters can be of much greater value in the prepara- 
tion of keys to the smaller subspecific entities and should 
be carefully noted and annotated by all collectors. 
Hevea rigidifolia and H. glabrescens have not been 
included in the key because they have yet to be seen in 
Colombia. Hevea Foxu has been omitted pending the 
collection of more material and information concerning 
its characters and relationships. 
KEY TO THE GENUS HEVEA IN COLOMBIA 
A. Leaflets horizontal or reclinate in relation to the petiole (some- 
times slightly erect in H. pauciflora var. coriacea). Latex nor- 
mally pure white (in H. viridis yellowish or white). Habitat: 
bogs, swamps or sterile and rocky locations. 
B. Capsules (ordinarily about 4 cm. or less in diameter) and seeds 
medium sized. Seeds 300-750 per kilo (except in H. pauci- 
flora var. coriacea). Disk of staminate flower well-developed. 
Inflorescence pubescent to nearly glabrous. Leaflets normally 
coriaceous or subcoriaceous. 
C. Leaflets ordinarily horizontal. Inflorescence pubescent, very 
rarely subglabrescent. Seeds under 360 per kilo. 
D. Leaflets variously pubescent beneath (usually reddish or 
DD. 
ferruginous). Buds of staminate flower acuminate. An- 
thers normally 7-9 (rarely 5-10) in two irregular verti- 
cels. Latex yields very elastic, high-quality rubber. Large 
trees of floodable forests. Seeds 330-360 per kilo, with 
large dark brown or black spots, somewhat elongate- 
ovoid, not angular. 
H. Benthamiana 
Leaflets glabrous beneath. Buds of staminate flower ob- 
tuse. Anthers normally 10 in two regular verticels. La- 
tex yields a sticky, non-elastic rubber of no commercial 
value. Medium sized trees of rocky or sandy locations in 
catinga forests. Seeds not seen for Colombian specimens 
but apparently larger than those of H. Benthamiana. 
H. pauciflora var. coriacea 
[ 16 ] 
