BOTANICAL MUSEUM LEAFLETS 
HARVARD UNIVERSITY 
CamsBripGre, MAssacHuseTTs, SEPTEMBER 8, 1947 Voi. 13, No. 1 
STUDIES IN THE GENUS HEVEA I 
BY 
RicHarp Evans ScHuu tes ' 
1. THE DIFFERENTIATION OF HEVEA MICROPHYLLA 
AND H. MINOR 
In 1899, Hemsley described and illustrated an unusual 
species of Hevea, naming it H. minor because of its small 
stature. The species was based upon fruiting material 
collected by Richard Spruce on the Rio Casiquiare in 
southern Venezuela. 
A few years later, in 1905, Ule described Hevea mi- 
crophylla, basing the species upon fruiting material which 
he had collected on the lower Rio Negro in Brazil. Five 
years later, the monographer Pax published variety typ- 
ica and variety major of this concept. 
In 1906, Huber (Bol. Mus. Goeldi 4 (1906) 683-634) 
suggested that Hevea microphylla might be synonymous 
with H. minor, pointing out several characters in which 
the two concepts, as described, agree. He admitted, how- 
ever, that there seemed to be differences in other charac- 
ters, so he chose ‘‘to consider HZ. microphylla a distinct 
species for the present.”’ Identifying a flowering collec- 
tion made by Ducke (Ducke 7027) in the lower Rio 
‘Agent (Botanist), Rubber Plant Investigations, Bureau of Plant 
Industry, Soils and Agricultural Engineering, Agricultural Research 
Administration, United States Department of Agriculture; Research 
Fellow, Botanical Museum, Harvard University. 
eo 
