Abstract: The pollination biology of Pedicularis L. was studied in the Zhongdian and Deqin counties of Northwest Yunnan in the summer of 1993. From late July to late August, 18 species of Pedicularis were found in full bloom, while P. integrifolia was almost out of bloom. A preliminary study of pollination biology of six species was conducted. The paper reports the results of four betterstudied species, among which P. tsekouensis Bonati and P. roylei Maxim. are of short-tubed, emstrate and nectarless corolla type and P. longifiora var. tubiformis ( Klotz. ) Tsoong and P. siphonantha var. delavayi (Franch.) Tsoong are long-tubed, rostrate and nectarless. The shorttubed P. tsekouensis and P. roylei were found exclusively by Bombus friseanus workers standing on the lower lips of the corolla and vibrating pollen from anthers concealed within the galea. The pollen deposited on the dorsal side of the head-thorax of the workers was transferred to the stigma of another plant by the insects nototribically. The long-tubed species were pollinated by Bomus rufofasciatus workers hanging inverted from the corolla and buzzing pollen, the stigma contacted pollen on the ventral side of the pollinator’s thorax. This falls into the stemotfibical pollination type. The blooming phenology of later-summer Pedicularis seems corresponding to the emergence of short-tongued bumblebee workers rather than longer tongue queens. Preliminary observations were made to check whether keptopteran insects were the pollinators of the very long-tubed species but no such phenomenon was found. The long-tubes of the yellow flowered P. longifiora var. tubiformis and those of the magentha flowered P. siphonantha var. delavayi may be just an adaptation in extending the rostrate vibration pollination mechanism beyond the relatively short plants. This seems a result of coevolution of these alpine plants and their pollinating bumblebees.

Key words: Pedicularis, Bombus, Pollination mechanism