Pollination Ecology of Pedicularis muscoides H. L. Li subsp. himalayca Yamazaki from Alpine Areas of Western Sichuan, China.

The pollination ecology of small, short, and two-flowered Pedicularis muscoides subsp. himalayca was studied during its full blooming period in alpine areas of western Sichuan Province, China, part of the putative origin and diversification center of the genus. Pedicularis muscoides subsp. himalayca was nototribically pollinated exclusively by queens of four bumblebee species (Bombus Latr.) that foraged for nectar on flowers in an upright position. Of the four Bombus species, B. friseanus Smith occurred in the highest frequency and was the major pollinator of P. muscoides subsp. himalayca. It comprised 81% of the bumblebees collected on P. muscoides subsp. himalayca. Queen bumblebees stood on the ground while foraging on flowers, which has not previously been reported in other Pedicularis species. During the study period almost all the foragers were confined to the studied subspecies and very occasionally visited other associated blooming species at the study site. The low plant height; outcurved terminal flowers; short-tubed, erostrate, and copiously nectariferous flowers; corolla morphology; and highly synchronized short-blooming period of P. muscoides subsp. himalayca made this plant well adapted to pollination by queen bumblebees within a short growing season. Thus this study provides evidence for coadaptation between Pedicularis and bumblebee pollinators. [ABSTRACT FROM AUTHOR]