Pollination and breeding systems of selected wildflowers in a southern African grassland community

Southern African grasslands harbour diverse plant communities, and recent studies have revealed remarkable plant–pollinator interactions in this biome. However, there has been no attempt to study community-wide patterns in breeding systems or plant–pollinator mutualisms. Here, we present the results of extensive field work on twenty-one wildflower species with large, showy flowers, belonging to a broad range of angiosperm families. Most of the plant species investigated were found to be self-incompatible and therefore completely dependent on pollinators. Based on over 250 h of field observations during which we recorded over 1000 individual insects, 368 of which were examined for pollen loads, we identified pollination systems involving, inter alia, bees and flies (both short- and long-tongued), wasps, butterflies, hawkmoths, beetles, and sunbirds. The most important pollinators of the wildflowers investigated in the community were long-tongued solitary bees. Several plant species appear to be dependent on a single or a few pollinator species, and few are true generalists. This high degree of specialisation indicates a well-structured pollination landscape, suggesting both a history of climatic and ecological stability and potential sensitivity to human disturbance.