Gynomonoecy in angiosperms: phylogeny, sex expression and evolutionary significance Male Flowers and Relationship between Plant Size and Sex Expression in Herbaria of Nomocharis Species (Liliaceae) Adaptive advantages of gynomonoecious species Adding time-calibrated branch lengths to the Asteraceae supertree Plant sexual systems correlated with morphological traits: Reflecting reproductive strategies of alpine plants Floral sex allocation and gynomonoecy of Ligularia (Asteraceae) in the eastern Qinghai-Tibet Plateau