Abstract: Gynomonoecy is the sexual system in which female and bisexual flowers occur on the same plant. Little attention has been paid to the adaptive significance of this sexual system. In this paper, we investigated 3 common species of the genus Ligularia (Asteraceae) in the eastern part of the Tibetan Plateau and examined the effects of flower head position, plant height and leaf removal on floral sex allocation. The results showed that plants of these three Ligularia genera were self-incompatible, and the intra-inflorescence variations in floral traits were significant. Regardless of whether the racemes developed from top to bottom or in the opposite direction, the early-formed flowers within a raceme were larger and displayed female-biased sex allocation. The later-formed flowers had more ovules and displayed a male-biased sex allocation. Taller plants have a lager flower display and invest more resources in the female state. Raceme size and investment in ray floret biomass were significantly decreased in plants with leaves removed. However, plant height and leaf removal did not change the variation of floral traits within inflorescences. The adaptive significance of gynomonoecy in Ligularia lies in permitting flexibility in allocation of resources to male and female functions. Ecologically this behavior may link seed set to resource availability and may assist with attracting pollinators, and may also reduce conflict between male and female functions.