Floral morphology and reproductive success in herkogamous Narcissus cyclamineus (Amaryllidaceae)

We studied the variation on floral traits of Narcissus cyclamineus, a species endemic to the northwestern Iberian Peninsula. We analyzed the effect of different breeding systems and the degree of herkogamy and stigmatic exertion on female reproductive success. Results showed that, while variation on floral structures is relatively low (i.e. less than 25% for all sterile structures), CVs for herkogamy and stigmatic exertion are much higher. We also found a considerable variation among populations in the relative position of stigmas and anthers and a significant effect of breeding system (facilitated autogamy, spontaneous autogamy or xenogamy) on fruit set and seed production. The number of seeds per fruit bears no relation with corona size, degree of stigmatic exertion or herkogamy. However, herkogamy showed a marginally significant effect on mean seed weight per fruit. The results highlight the need to analyze the influence of continuous variations in the position of floral organs on the reproductive success of the monomorphic species of the genus Narcissus.