The evolution of complex floral morphology in orchids can be attributed largely to mechanisms that ensure precise placement of pollinaria on the bodies of animal flower visitors. Floral advertisements and rewards also play a key role in selective attraction of animals that are suitable as pollen vectors. Previous studies of the large African orchid genus have demonstrated high levels of pollination system specialization and have identified functions of floral morphology for transfer of pollen, but studies of pollination in members of the tropical clade of sect. have been lacking. This clade is characterized by highly unusual floral morphology, including vertical anthers and pronounced spatial separation between a nectar-producing spur located in the centre of the dorsal sepal and the rostellum lobes that serve to attach pollinaria to flower visitors. In a study conducted in central Zambia, I found that the flowers of are pollinated by large wasps (Eumeninae and Scoliidae) and carpenter bees. These insect groups carry pollinaria near the tip of their abdomen, which contacts the rostellum when the abdomen is tucked under the flower for balance during nectar-feeding. The pollinaria are rigid and project at 90˚ from the underside of the abdomen such that they contact the deeply recessed stigma during subsequent flower visits. This study reveals a new mechanism of pollen transfer in and sheds light on the evolution of the highly complex floral morphology of this large orchid clade

中文翻译：

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Disa engleriana（兰科）的授粉：对大型蜜蜂和黄蜂腹部的花粉沉积进行花卉改良

兰花复杂花形态的进化很大程度上归因于确保花粉块精确放置在动物花客身体上的机制。花卉广告和奖励在选择性吸引适合作为花粉载体的动物方面也发挥着关键作用。先前对大型非洲兰科植物的研究已经证明了授粉系统的高度专业化，并确定了花形态对于花粉转移的功能，但对热带分支成员授粉的研究却很少。一直缺乏。该分支的特征是非常不寻常的花卉形态，包括垂直的花药以及位于背萼片中心的产花蜜的支刺和用于将花粉附着于花客的喙裂片之间明显的空间分离。在赞比亚中部进行的一项研究中，我发现大黄蜂（Eumeninae 和 Scoliidae）和木蜂为花授粉。这些昆虫群在其腹部尖端附近携带花粉质，当腹部在花蜜采食期间被塞到花朵下方以保持平衡时，花粉质会接触到喙部。花粉块是刚性的，从腹部下侧突出呈 90°，以便在随后的开花过程中接触到深深凹陷的柱头。这项研究揭示了花粉转移的新机制，并揭示了这种大型兰花分支高度复杂的花卉形态的进化