Revisional study of neotropical Beilschmiedia species (Lauraceae ...

spinules, exine is ectexinous, intine is a dominant layer of the pollen wall and uniformly
thick, possibly equally suited for pollen tube egress.
But these species (and Mezilaurus) are different from the other genera in size of
spinules and in surface of the basal cushions and exine. Size of the spinules is relatively
large, 1-1.5 j.lm long. Surface of the basal cushions and exine is without granular processes.
Grain size of B. 1niersii is reported as the largest of all the species they studied. Density
of spinules is reported as one of the lowest in their study.
Karyology
Among neotropical Beilschmiedia species, only B. berteroana has been reported in
chromosome number. The chromoson1e number is x = 12 (2n = 24) (Raven 1975), which
is con1mon in the Lauraceae species. Polyploid numbers have not been found in
Beilschmiedia.
Distribution
Beilschmiedia species distributed in the neotropical counties are listed in Table 1.
In the neotropics, Beilschmiedia ranges from central Mexico to southern Brazil and
Chile. Beilschmiedia is absent from An1azon basin and northern Chile, therefore the
distribution appears to consist of one large region from central Mexico to western Bolivia,
and sn1all regions in northern South America, south-eastern Brazil and central Chile (Fig. 6).
In north-western Latin America, distribution of Beilschmiedia ranges from central
Mexico to western Bolivia (Fig. 6 A). The country with the highest number of species is
Costa Rica, where eight species occur. Six of these species have also represent from
Panarna, and four of them are also distributed from Venezuela to Ecuador. On the other
hand, only two of the Costarican species, B. ovalis and B. pendula, extend the distribution
north of Costa Rica (to Honduras). Beilschmiedia pendula is the species with the widest
distribution in neotropical Beilsch1niedia species, which occurs from Honduras to Ecuador,
including the West Indies. In Mexico there are six species present, four of which are
enden1ic to Mexico. In the Guianas, there are two species distributed; B. curviramea is
known from eastern Venezuela to Guyana (Fig. 6 B), and B. hexanthera is known only from
French Guiana (Fig. 6 C).
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