Supplement 1. Original data on heterospecific pollen transfer, floral traits, pollination generalization level among 74 species, and parameters of the HPT network structure.

File List Directed_network.txt (MD5: 5397bbc1e9c459809a79f42456a4318c) Floral_trait_and_PG.txt (MD5: f883673e7890eaf6849467f2fdb52fbb) Description Directed_network.txt is an original data set of pollen donation and receipt among 74 flowering species in Shangri-La Alpine Botanical Garden, southwest China. Value in each cell represents the number of pollen grains transfered between plant species. Species number is corresponding to that in Fig. 2. Floral_trait_and_PG.txt presents data including relative visit frequency of major pollinators (Bee, bumblebee and Diptera) to 74 sympatric flowering species, pollination generalization level, floral traits (stigma area, stigma position and corolla open), (weighted) In- and Out-Degree, and Modularity. Species whose stigma were collected shown in 1 otherwise in 0.