Abstract: In order to explore the relationship between the pollinator and pollination
syndromes, and to evaluate the possibility of predicting likely pollinators based on pollination
syndromes, the pollination biology of Paphiopedilum dianthum was examined. This species
shares a close phylogenetic relationship, similar habit, and a recognizable syndrome of floral
features (including helmet-shaped labellum, big dorsal sepal, and black warts or hairs on
petals) with other brood-site deceptive Paphiopedilum species. According to the pollination
syndrome concept, P. dianthum would be pollinated by hoverflies and attract pollinators with
brood-site deception. Results were consistent with this prediction. Paphiopedilum dianthum
was mainly pollinated by female hoverflies (Episyrphus balteatus), and these flies were
indeed lured by the false brood-site on the orchid flower. It is suggested that the pollination
syndrome may be correlated with pollination selective pressure, but not simply with pollinator
species, and that accurate prediction requires consideration of all factors influencing floral
characters, including habit and evolutionary history.

Key words: pollination syndrome, Paphiopedilum, selection pressure, pollinator, phylogeny,