extremely poisonous, until boiling breaks down the cy- 
anie substances. They are also extremely rich in oil. 
There is one important aspect of VVaupesia cataracta- 
rum which is still a puzzle. Sometimes a white, watery 
latex is present in the bark of the basal part of the trunk, 
but usually no trace of such a latex can be found. When 
present, it is a curiously resinous liquid drying to form 
a rather chalky white substance which easily crumbles in 
the hand. One tree (Schultes & Cabrera 13339) had a 
watery latex of a reddish color in the trunk, whereas 
nearly all of the more than eighty trees which I examined 
closely in the several localities possessed this reddish latex 
abundantly in the terminal branches, even when no evi- 
dence of it could be found elsewhere in the plant. Infor- 
mation from the Indians indicates that these anomalous 
conditions are not seasonal, and my own studies convince 
me that there is no relationship between the presence or 
absence of latex and its color and ecological factors. At 
first, I suspected that perhaps distinct varieties or forms 
might explain the problem, but there is no morphologi- 
cal evidence that we have at hand any taxonomic vari- 
ants. In thus reluctantly leaving this interesting puzzle 
unsolved for the present, | must emphasize again the 
presence in Joannesia heveoides of a very similar thin, 
watery, red latex. Joannesia, of course, does not have 
the white latex common to all of its presumed allies, nor 
do these allies—Hevea and Micrandra— possess the red 
latex of Joannesia and Vaupesia. 
The drawing of Vaupesia cataractarum and the dis- 
tribution map published herewith were made possible 
through a grant from the United States Department of 
Agriculture with which I was associated when this new 
genus was discovered. I wish to express my appreciation 
to Dr. Julian A. Steyermark for his interest and advice 
in my treatment of this new concept. 
Reprinted November 1970. [ 86 ] 
