Reproductive biology of Pedicularis (Scrophulariaceae) in the Sichuan Himalaya

Abstract

AbstractIn 1997–1998, the reproductive biology of Pedicularis bidentata, Pedicularis cranolopha, Pedicularis davidii, Pedicularis longiflora var. hongyuanensis, Pedicularis longiflora ssp. tubiformis, Pedicularis plicata, Pedicularis polyodonta, Pedicularis rhinanthoides ssp. labellata, Pedicularis roylei, Pedicularis semitorta, Pedicularis spicata and Pedicularis verticillata was studied in the subalpine–alpine zone of the Chinese Himalaya in western Sichuan Province. Except for Apis pollinators on P. polyodonta and P. spicata, only workers and queens of Bombus filchnerae, Bombus patagiatus, Bombus potanini, Bombus sichelii and Bombus waltoni pollinated Pedicularis. Nectariferous, erostrate flowers were pollinated nototribically and sternotribically, during foraging for nectar and pollen, respectively, whereas nectarless, rostrate (including very long‐tubed) flowers were pollinated sternotribically during foraging for pollen only. Insect exclusion from flowers revealed that P. longiflora ssp. tubiformis, P. roylei and P. verticillata are insect‐pollinator dependent. Analysis of the corbicular pollen loads of pollinators revealed a moderate degree of pollen‐foraging fidelity. Pollinator frequency on Pedicularis did not exceed three insects per hour, but Bombus pollinators were more common on other plant genera. No evidence of lepidopteran pollination on long‐tubed Pedicularis species was found, nor was there any evidence of species–species specificity between Bombus pollinators and Pedicularis flowers.