up of one species, H. guianensis: and Section Bisiphonia (the 
same as Baillon’s Section Bisiphonia) comprising what are now 
knownas H. Benthamiana, H. brasiliensis ,H. guianensis var. 
lutea, H. pauciflora, H. rigidifolia and H. Spruceana. In 1866, 
he revised his family classification of the Euphorbiaceae but 
maintained his earlier infrageneric classification of Hevea with 
the same number of species. His only change in treatment 
consisted in a grouping together of the species of Section 
Bisiphonia, according to the shape of the staminate buds: H. 
Spruceana (with subovoid, obtuse buds with a calyx laciniate 
for only slightly more than half its length): H. pauciflora (with 
ovoid, obtuse buds, with a calyx divided for 2/3 and 3/4 its 
length); and H. rigidifolia, H. Benthamiana, H. brasiliensis 
and H. guianensis var. lutea (with oblong-conic-ovoid and 
acute buds, apically slightly twisted). Again, in 1874, Mueller 
divided the genus, as he had done previously, into Euhevea (H. 
euianensis) and Bisiphonia (all other species). At this time, he 
arranged the species in Bisiphonia into only two groups: those 
with staminate buds obtuse (H. Spruceana, H. pauciflora) and 
those with buds acuminate (H. rigidifolia, H. nitida,H. Benth- 
amiana. H. brasiliensis and H. guianensis var. lutea). 
No further attention was apparently given to infrageneric 
classification of Hevea until 1906, when Huber initiated his 
detailed studies of the genus. Huber, the first botanist ac- 
quainted with living trees in their native habitat to consider 
Hevea generically from a taxonomic viewpoint, followed the 
earlier division of Hevea into Euhevea and Bisiphonia. Under 
Bisiphonia, however, he made three Series, giving them tech- 
nical Latin designations. Into Series Luteae he put what he 
recognized as H. lutea, H. apiculata, H. cuneata, H. Benth- 
amiana, H. Duckei, H. paludosa and H. rigidifolia: with an- 
thers in two incomplete whorls and staminate buds acuminate: 
these specific concepts he separated into three groups on 
characters in the disk of the staminate flower. Series /nter- 
mediae comprised his H. minor, H. microphylla, H. Randiana 
and H. brasiliensis: with anthers in two complete whorls and 
acuminate buds: these species he divided into two groups, 
based on characters in the style. His Series Obtusiflorae in- 
cluded what he recognized as H. Spruceana, H. discolor, H. 
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