Pollen Morphology in the Order Centrospermae

Pollen of 190 species from 16 families has been examined by light and scanning electron microscopy. Three basic pollen types were found: 3-colpate, pantoporate, and pantocolpate, all with a spinulose and tubuliferous/punctate ektexine. The palynological data emphasize the close relationship of the betalain families, and support their association with the anthocyanin families. Caryophyllaceae and Molluginaceae. Pollen morphology reinforces the placement of the Cactaceae and Didiereaceae in the order, and would support the inclusion of Dysphania in the Chenopodiaceae. The pollen grains of the Achatocarpaceae, Bataceae, Gyrostemonaceae and Theligonaceae, none of which had the spinulose and tubuliferous/punctate ektexine, had no counterparts in the remaining taxa examined. Thus, the evidence from palynology does not support their inclusion in the Centrospermae and indicates that their placement should be re-examined.