REPRODUCTION AND POLLINATION IN CENTRAL-EUROPEAN POPULATIONS OF SILENE AND SAPONARIA SPECIES

Flower morphology, flowering phenology, flower visitors, reproductive systems, and stigmatic receptivity of six species of Silene and Sapona ria (Silene alba, S. dioica, S. vulgaris, S. nutans, S. noctiflora, Sa ponaria officinalis) were studied from April to October 1993 and from April to June 1994 in natural populations around Giessen in Hessen/Cen tral Germany and, additionally, in individuals grown from seeds in the Botanical Garden of the University of Giessen. With the exception of Saponaria officinalis and S. noctiflora, all species were regularly vi sited and pollinated by crepuscular and nocturnal moths and hawkmoths, but only one species, S. alba, was exclusively pollinated by these ni ght-active insects. The other species showed mixed pollination syndrom es in which nocturnal and diurnal insects both promoted pollen transfe r. Geitonogamy or even autogamy occurred in the gynodioecious and herm aphrodite species S. vulgaris, S. nutans, S. noctiflora, and Saponaria officinalis. Silene noctiflora, the only annual species, is pseudocle istogamous; the majority of its flowers did not open, and fruit set oc curred after selfing in bud.