Gynomonoecy in Silene italica (Caryophyllaceae): Sexual Phenotypes in Natural Populations

Abstract

Abstract: Some gynodloecious species present not only hermaphrodite and female individuals but also gynomonoecious individuals that produce both female and perfect flowers. In a study of natural populations of Silene italica, we found that gynomonoecious individuals were common in all populations (from 13 to 39%) and that their frequency was independent of the frequency of females. No relationship was found between the number of flowers a plant produced and its sex. The majority of gynomonoecious individuals showed a low proportion of female flowers but all proportions were found. Female flowers of these individuals were well‐developed flowers that set fruit as often as female flowers on pure females. The percentage fruit set was characteristic of the type of flowers (around 56% for perfect flowers and 76% for female flowers) whatever the sex of the individual plant. The determination of sex is not known but data indicate that environmental conditions could be responsible for a shift between the hermaphrodite and the gynomonoecious states rather than between the female and the gynomonoecious states.