The pollination ecology of fourteen species of Pedicularis (Scrophulariaceae) was studied in the subalpinealpine zone of the Sichuan Himalaya. Bumblebees (Bombus Latr.) sternotribically pollinated rostrate, nectarless species with very long corolla tubes by scraping pollen. Pollinators on short‐tubed, nectarless, rostrate species scraped or vibrated pollen, and nectariferous species were pollinated nototribically by nectar foragers or sternotribically by pollen foragers. Stigmas contacted residual pollen in the midline of the insect body. No evidence of lepidopteran pollination was found in any Pedicularis species. Pedicularis floral structure and function are considered to have coevolved with foraging selection by bumblebees, but pollination syndromes are not specific for a single bumblebee species nor are Bombus foragers restricted to a single plant species. Analysis of corbicular pollen loads of foragers on Pedicularis revealed a moderate degree of flower constancy, especially among foragers on nectarless flowers, probably contributing to speciation in the genus. Up to nine Pedicularis species flowered sympatrically and synchronously, and some species exhibited microhabitat selection. No putative hybrids were identified. Concepts of floral evoution in Pedicularis are in need of revision in light of new evidence presented here.

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. International Association for Plant Taxonomy (IAPT)is collaborating with JSTOR to digitize, preserve and extend access to Taxon. SummaryBorn over 200 years ago the science of anthecology (pollination ecology) has developed new concepts in the last 50 years using quantified information from studies of insect sense perception and behavior. Flower-insect coadaptation is considered a continuing process in which changing interrelationships establish and remove reproductive barriers in breeding systems at the vital link of pollen transport. Convergent evolution is apparently reflected in the development of similar pollination mechanisms in unrelated plant taxa through pollinator sharing, floral mimicry, and synchronous anthesis of sympatric spscies. Reproductive isolation of plant taxa is suggested in diversity and versatility of pollinator behavior, unsynchronized anthesis, and functional as well as structural differences in pollination mechanisms. Contributions of anthecology to systematics are primarily useful for a fuller understanding of the origin of taxonomic entities and secondarily in defining criteria for their establishment.

In 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 insectpollinator 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.

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