The reproductive biology of Psychotria barbiflora was investigated from April/1999 to September/2000, in the Dois Irmãos State Park, Recife, Pernambuco State, Brazil, an Atlantic Forest remnant. Psychotria barbiflora is a understory species (0.5-2.0m tall), which flowered between April and July and fruiting from June to September. The species presented heterostyly (distyly), and the flowers are arranged in terminal, pendant inflorescences, wrapped in bracts, which are greenish during the flowering period and become purple during the fruiting phase. Anthesis began at about 4:30 a.m. and the flowers last until 1:00 p.m. Recorded nectar volume were c. 0.80 and 0.60µl and sugar concentration was approximately 22 and 24%, respectively, in long and short-styled flowers. The floral morphs were similar in corola size but short-styled flowers had larger, less numerous pollen grains when compared to long-styled ones. Psychotria barbiflora is a mellitophylous species, pollinated by three bee species which were observed collecting nectar and pollen, and also by a wasp species, which collected only nectar, in both floral morphs. Based on the results of hand-pollination tests and observations of pollen-tube growth, it can be concluded that this species has sporophytic self-incompatibility.
heterostyly; pollination; Psychotria; reproduction; Rubiaceae; pollen-tube
