Pollination of the “carrion flowers” of an African stapeliad (Ceropegia mixta: Apocynaceae): the importance of visual and scent traits for the attraction of flies

摘要: Flowers that mimic carrion or faeces exhibit unusual traits, the evolution and functional significance of which remain poorly understood. Odour is an important pollinator attractant, but visual traits interactions between scent have seldom been considered. We studied pollination “carrion flowers” Ceropegia mixta [= Orbea variegata], analysed floral used manipulative experiments to explore contributions attraction. Flowers were pollinated primarily by Musca domestica (Muscidae), with lesser Calliphoridae Sarcophagidae flies. The odour (analysed using gas chromatography–mass spectrometry) was dominated oligosulphides phenol. Comparison abiotic background colours reflectance a fly colour vision model suggested that flowers would be chromatically indistinguishable from background. arrival rates at concealed (but still scented) versus exposed showed flies can locate without cues, visitation higher when visible. Experiments supplied real (to dark spots on pale background, both occur frequently in flowers that faeces) scented black attracted significantly more than similarly human-yellow flowers, while presence size corolla had no effect attraction Our results suggest there component attraction, some such as mottled patterning, may not evolved enhance