(Pollen morphology of the tribe Bursereae (Burseraceae) in South America). The neotropical genus Bursera (L.) Jacq. comprises seven species in South America. Commiphora Jacq., distributed mainly in the less humid parts of the tropics and subtropics of Africa and Asia, is only represented by C. leptophloeos (Mart.) Gillet. Pollen grains of five taxa of Bursereae were examined. The pollen material was acetolyzed, measured, described and photographed by light microscopy and, in most cases, also by electron microscopy scanning. The data obtained was statistically analysed by methods according to sample sizes. The pollen grains of Bursera are generally small, prolate-spheroidal, aspidote and with circular ambit, brevicolpate, striate or striate-reticulate. The studied species could be distinguished through differences in the ornamentation of the exine, the form of the endoaperture and the size of the pollen grains. The pollen grains of C. leptophloeos are of intermediate size, oblate spheroidal, subcircular ambit, moderately long colpi, and lolongate endoapertures with costa and retipilate ornamentation. The tribe Bursereae is eurypalynous.
Burseraceae; Bursera; Commiphora leptophloeos; pollen grains
