a caoutchoue et a gutta’’ (1908) 132) repeated Huber’s 
statement that Hevea rigidifolia yields a good rubber. 
La Rue (USDA Bull. 1422 (1926) 8) included Hevea 
rigidifolia in a list of species yielding ‘‘fair to good rub- 
ber,’’ but there seems to be no basis for this statement. 
Spruce (in Hooker’s Journ. Bot. ser. 8, no. 6 (1854) 871) 
merely remarked that it is ‘‘a milky tree of 80 feet.”’ 
Pittier (loc. cit.) enumerated three species of Hevea 
for the flora of Venezuela: HI. Benthamiana, H. minor 
and H. rigidifolia, but, as stated above, it is doubtful 
that his report of the last-named species is based on cor- 
rectly determined material; it refers probably to A. 
pauciflora var. coriacea. However this may be, Pittier 
writes that (translated) ‘‘of the three, the two first seem 
to give good rubber, but we know nothing about the 
third. It is probable that all take part in rubber produc- 
tion in the country.”’ 
The field data annotated on Frédes 21394 indicate 
merely ‘“‘latex branco, abundante, coagulavel,’’ and 
Foes 21401 adds that the species can be ‘‘rica em latex 
branco, coagulavel.”’ 
In writing of several of his caatinga collections, Frées 
(‘‘Excursio botanica ao alto Rio Negro’’ Mss. report to 
Dr. Felisberto C. de Camargo (June 4, 1946) 28) states 
(translated): ‘‘T'he Heveas of the forest at Javarité 
(21231, 21249, 21251, 21253) which are also common in 
the stretches of forest at Caiary-Aiary are low, measuring 
hardly 5 or 6 meters by 10 to 12 centimeters in diameter 
at breast height, with heavy and reclinate foliage, with 
medium-sized fruits as can be seen from the specimens 
collected in the region of the Rio Icana, in caatingas 
similar to those of Caiary-Aiary; they certainly must 
be little known because of the restriction of this species 
to its peculiar habitat. These forms of Hevea have, in 
themselves, no commercial importance because besides 
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