Peculiarities of the Inner Calyx Surface of Caryophylloideae with Special Regard to Sexual Dimorphism in two Dioecious Species*

Abstract

The structure of the inner calyx surface of several Silene and one Saponaria species with different sex expression have been investigated by scanning electron microscopy. Some of the hermaphroditic and gynodioecious species show peculiarities in the basal parts of their calyces, such as cylindrical trichomes in Si. nutans. Capitate trichomes occur exclusively on the inner calyx surface of the two dioecious species Si. dioica and Si. latifolia ssp. alba. In both species the density of these trichomes is significantly higher in female than in male individuals. The hypothesis is proposed that these trichomes play a role in flower discrimination of specialized pollinators and seed predators.

Key words

Silene - Saponaria - calyx - trichome - sexual dimorphism - host recognition