are extremely coriaceous with strongly recurvate margins, 
as in Hevea rigidifolia, and although they are much 
smaller and more narrowly lanceolate-elliptic, they could 
very easily be misidentified (without fertile parts) as 
Hi. rigidifolia. The seeds and capsules of this collection, 
however, unquestionably belong to the concept Hevea 
Benthamiana; they are much smaller than in typical 
Hevea Benthamiana, but they are perfectly ovoid and are 
yellowish or light golden tan with large reddish brown or 
brownish black spots. The tree, eighteen or twenty 
meters tall, had sparse yellowish latex. It grew along a 
brooklet at the edge of asavanna. According to Ducke, 
the coriaceous character of the leaflets of this variant was 
gradually lost as one penetrated farther into the more 
densely forested igap6. This collection, as the analagous 
Barcellos material mentioned above, provides us with in- 
teresting data for a consideration of xerophytic parallel- 
isms in Hevea. It is entirely possible, too, that this un- 
usual form of Hevea Benthamiana which, at our present 
state of understanding, we call a parallelism, may be 
fundamentally significant as indicative of some actual 
relationship between Hevea Benthamiana and H.rigidi- 
folia. 
Possible economic and scientific importance 
of Hevea rigidifolia 
Little is known of the economic value of Hevea rigid- 
ifolia. Ducke (in Rev. Bot. Appl. 9 (1929) 628) intimated 
that the species “‘semble fournir du caoutchouc,’’ but 
naturally he could make no mention at that time as to 
whether or not it was ever exploited. Huber (in Bol. 
Mus. Paraense 4 (1906) 633) stated that Hevea rigidi- 
folia: ‘‘foi designada ao Sr. Ducke como fornecendo bor- 
racha b6éa,’’ but this statement was made in reference to 
a collection from Barcellos which was misidentified as 
A, rigidifolia (Ducke loc. cit.). Jumelle (‘‘Les plantes 
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