XVI International Botanical Congess

An unusual stylar dimorphism, characterized by variation in stigma height but not anther height, occurs in Narcissus. We investigate floral variation, morph-ratio distribution, self-sterility & fertility in 2 Narcissus spp. in. S. France. Although sex organ deployment is similar in the species, other features of their sexual systems differ dramatically. N. assoanus populations are long-biased or 1L:1S whereas N. dubius populations are L-biased or monomorphic L. N. assoanus is moderately self-sterile but cross-compatible with other plants regardless of morph. N. dubius is not self-sterile. We found no morph-specific differences in female fitness (selfing rate, fecundity). Thus, differences in male fertility are likely responsible for morph-ratio variation. To explain this, we present a genetic model which incorporates between & within morph mating.