flora or incorporated with Hf. paueciflora var. coriacea. 
For many years, there has been some uncertainty as 
to just what the concept which Hemsley called Hevea 
minor represented. This species was based on a single 
specimen trom the Rio Casiquiare in southern Venezuela, 
preserved in the Kew Herbarium. During the greater 
part of the present century, the erroneous belief that 
Hevea minor and H. microphylla Ule were identical was 
accepted. A recent study (Schultes in Bot. Mus. Leafl. 
Harvard Univ. 18 (1947) 1) of type and authentic ma- 
terial has shown that Hevea microphylla is indeed distinct 
from HZ. minor. There still remained some doubt, how- 
ever, as to whether or not Hevea minor represented a 
distinct species or a variant of some described concept. 
The paucity and apparent immaturity of the type and 
only specimen of HZ. minor made it unwise to conjecture. 
During the work in the upper Rio Negro basin in 1947 
and 1948, I collected flowering and fruiting specimens 
from a number of caatinga-trees which are almost exact 
matches for the type of Hevea minor. One of these col- 
lections GSchultes & Lopez 9489) came from a small tree 
at Cocuy, not far from the mouth of the Casiquiare and 
may, therefore, be considered almost topotypical: it 1s 
one of the collections most closely resembling Spruce 
3457, the type of Hevea minor. Twas unable to pene- 
trate the Casiquiare itself, but many natives informed 
me that the riverside caatingas of the Casiquiare abound 
with this small rubber tree. It is found in abundance in 
most caatingas in the Rios Curicuriari and the Uaupés, 
and upstream in the Rios Negro and Guainia. There is 
considerable variability in size of the trees, those growing 
in low-lying sandy caatingas which are flooded part of 
the year being extremely small, seldom exceeding fifteen 
feet in height. 
The type of Hevea minor was in fruit and with seed. 
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