Pollination ecology of Aconitum gymnandrum (Ranunculaceae) at two sites with different altitudes Highly efficient pollination by bumblebees ensures seed production in Pedicularis lachnoglossa (Orobanchaceae), an early-flowering Himalayan plant Are long corolla tubes in Pedicularis driven by pollinator selection? Flower Color Polymorphism in Rhododendron cyanocarpum (Ericaceae), an Endangered Alpine Species Endemic to NW Yunnan, China Sexual interference in two Chamerion species with contrasting modes of movement herkogamy Species diversity and colony characteristics of bumblebees in the Hebei region of North China. Pollination ecology of Gentiana straminea Maxim. (Gentianaceae), an alpine perennial in the Qinghai-Tibet Plateau