Reproductive biology and pollination of three species of Combretum Loefl. (Combretaceae)

The reproductive biology and pollination of three species of the genus Combretum were studied in natural populations, in areas of Caatinga (C. leprosum Mart. and C. pisonioides Taub.) and Atlantic forest (C. fruticosum (Loefl.) Stuntz) in Pernambuco and Paraíba states, northeastern Brazil. All the species presented continuous flowering after the rainy season. The colors of the flowers change during the anthesis period. Sugar concentration in the nectar is about 20.9% (sd = 2.08) in C. pisonioides, 21.3% (sd = 2.97) in C. leprosum and 9.6% (sd = 0.86) in C. fruticosum. The three species are self-incompatible. Pollen viability is higher than 95%. The flowers of C. pisonioides and C. leprosum have mellittophilous attributes. C. pisonioides is pollinated by wasps of the genus Polybia. C. leprosum is pollinated by ca. 20 species of Hymenoptera and Lepidoptera. Apis mellifera (Apidae) was the most frequent visitor to the flowers of this species. C. fruticosum is ornithophilous, pollinated by passerine birds (Coerebidae) and hummingbirds (Chlorostilbon aureoventris).

Combretum; pollination; mellittophily; ornithophily; caatinga; Atlantic forest