Flowering Phenology and Observations on the Pollination Biology of South American Cacti. 1.Denmoza rhodacantha

Abstract

Summary: Pollination biology is an especially important component of the overall ecological setting of a plant species since it has direct implications on reproductive success. Over time, a typological approach to classifying flower—pollinator interactions in the form of “floral syndromes” has been developed, and considerable predictive power is traditionally ascribed to these syndromes. Recent studies have increasingly questioned both the predictive value of the syndrome concept, as well as the underlying notion of increasing specialization amongst flower-pollinator interactions. The casual discovery that the seemingly ornithophilous flowers of the globose to shortly columnar South American cactus Denmoza rhodacantha (Cactaceae: Cactoideae: Cereeae: Trichocereinae) are visited by solitary pollen-collecting halictid bees, rather than the expected hummingbirds, adds another example to the growing body of mismatches between floral syndrome and observed pollinator.