Abstract
A study of the floral anatomy and pollen morphology of both species of the endemic New Caledonian genusOncotheca was undertaken to provide a more thorough and accurate generic description and to make additional comparisons of the two species. In general, flowers of the species are histologically similar, althoughO. macrocarpa has a strong tendency to possess more numerous and widely distributed tanniferous cells and druses.Oncotheca macrocarpa also differs fromO. balansae in possessing the important feature of unfused ventral carpellary bundles. The unspecialized, 3-colporate pollen type of the two species is very similar in size and surface pattern, has clearly delineated wall layers, and is in harmony with the recent consensus opinion thatOncotheca is most closely related to the Theaceae and allies, although the genus is probably best interpreted as an isolated taxon linking the orders Theales, Ericales, and Celastrales.
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Dickison, W.C. Further observations on the floral anatomy and pollen morphology of Oncotheca (Oncothecaceae). Brittonia 38, 249–259 (1986). https://doi.org/10.2307/2807350
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DOI: https://doi.org/10.2307/2807350