PHENOLOGY AND POLLINATION BIOLOGY OF 5 RANUNCULUS SPECIES IN CENTRAL GERMANY

Five Ranunculus species, R. acris, R. auricomus, R. bulbosus, R. flamm ula, and R. repens were studied in respect to phenology and pollinatio n biology at several places in their natural habitats around Giessen ( 50 degrees 35'N, 80 degrees 41'E), Central Germany, and at garden-beds of Giessen University in 1989. For R. auricomus, R. bulbosus, and R. acris quite distinct phenologies were observed at the two sites, with a much longer flowering period at the bed site. Flower visiting insect s, belonging mainly to the Diptera, Hymenoptera, and Coleoptera, varie d considerably in the natural habitats and at the bed sites. The great variety of flower visiting insects and the substitution of insect spe cies at different sites are an expression of a generalistic pollinatio n syndrome of the studied Ranunculus species.