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A great diversity of flower morphology in orchids has long been thought to be selected by diverse pollinators. Habenaria Willd. (Orchidaceae) species are generally characterized by long nectar spurs and pollinated by long‐tongued insects (Lepidoptera), the mechanical fit between the spur and pollinator proboscis length being supposedly caused by "arms race" reciprocal selection. Here, we report that flowers of Habenaria aitchisonii Rchb. f. with nectar spurs (approximately 9 mm) were pollinated by three species of settling noctuid moths whose proboscises varied in length from 10 to 16 mm. When a settling moth crawled on the spikes and probed the flowers for nectar, pollinia were placed on the moths' legs rather than on other body parts. Our 5‐year survey of pollinia movement and 3‐year supplemental pollination experiments indicated that fruit and seed production in this orchid were not often pollen‐limited at flower level. In a natural population in Shangri‐La, Southwest China, the proportions of pollinia removal and deposition on stigmas by moth legs were 93.8% and 83.5%, respectively. This finding of efficient pollen transfer by the pollinators' legs in H. aitchisonii adds a new example of diverse pollinia placement on pollinators (here settling moths) in the Orchidaceae. [ABSTRACT FROM AUTHOR]

The geographical distribution of pollinators is an important factor determining the biogeographical pattern of floral evolution and diversification. In Africa, a guild of plant species has converged in a floral syndrome for pollination by long‐tongued hawkmoths (predominantly Agrius convolvuli). It is hypothesized that such floral convergence could track the geographical distribution of long‐tongued hawkmoths, so it may not be confined to Africa. We investigated the pollination biology of Lilium sargentiae E. H. Wilson, which is endemic to China and exhibits traits suggestive of long‐tongued hawkmoth pollination. Lilium sargentiae was visited by A. convolvuli as well as small beetles (Nitidulidae) but pollination was mostly or totally effected by the moth. It was consistent with other hawkmoth‐pollinated plants in terms of floral tube length, nectar traits, tepal reflectance, and scent composition. We present the first experimental evidence for the hypothesis proposed above and for hawkmoth pollination in the widespread and ornamentally and economically important genus Lilium L. in a natural habitat. Our findings imply that long‐tongued hawkmoths (especially the extremely widespread A. convolvuli) as a distinctive pollinator niche may have underlain the evolution of long‐tubed (>8 cm) flowers across different continents. [ABSTRACT FROM AUTHOR]

Floral divergence among congeners may relate to differential utilization of pollinators and contribute to reducing overlap in pollination niches. To investigate whether and how floral differences are associated with differential utilization of pollinators in three sympatric Adenophora species, we analyzed floral traits and evaluated the contribution of different visitors to pollination. We compared visitation rates of different pollinator categories in different years and sites. A suite of floral traits differed among the three Adenophora species, suggesting adaptation to diurnal versus nocturnal pollination and an intermediate condition. However, many visitor species were shared among the three plant species, suggesting that floral traits did not rigorously filter visitors. Effective pollinators were large bees and moths. The importance of large bees as pollinators decreased whereas that of moths increased along the gradient from typically bee-pollinated to moth-pollinated flowers. The intermediate species ( A. khasiana) differed substantially from the other two species in pollinator species but not in pollinator categories. The principal pollinator category of each species was constant across years and sites except in the intermediate species where it differed between two sites. Overall, the three sympatric species of Adenophora partition pollinators by floral divergence and the principal pollinators coincide with the predictions based on floral syndromes. [ABSTRACT FROM AUTHOR]