XVI International Botanical Congess

Beetle-pollinated species of these four families, especially those with nocturnal anthesis, show notable similarities in morphological and physiological characters of inflorescences and flowers, which appear to have evolved by convergence. All species are protogynous, both the hermaphrodite flowers of the Annonaceae and the dichogamous inflorescences of the other families. The dichogamy forces cross-pollination. The strong flower odors, promoted by remarkable temperature elevations (thermogenesis), attract the pollinating beetles during the initial female stage. In species of Annona, Duguetia, Philodendron, Carludovica, and others, large dynastid scaarab beetles are exclusive pollinators. In some species of palms (Astrocaryum, Attalea, and Bactris) however, the dynastids are only additional pollinators to nitidulids and curculionids.