Sistema de polinização e reprodução de Byrsonima Sericea DC (Malpighiaceae)

Abstract

The pollination, the reproductive system and the flowering phenology of Byrsonima sericea DC. were studied from October/1997 to February/1998 in the Ecological Reserve of “Dois Irmãos”, in Recife (PE). Byrsonima sericea is a woody species (3-20 m tall), flowering from October to February. The flowers are hermaphrodites, zygomorphic, arranged in terminal inflorescence, of the raceme type. The corolla is yellow and has five clawed and fringed petals. The superior one is modified as a flag. The calyx has five sepals with 10 elliptic epithelial oil glands, the elaiophores. In some individuals these elaiophores are absent. The androecium has 10 stamens, the anthers are rimoses and the dehiscence occurs at the pre-anthesis phase. Pollen viability was 93,3% and 98,3%, respectively to individuals with and without elaiophores, the number of pollen grains per anther was 1.216,66 and 923,33, and the pollen/ovule (P/O) ratio was 308.000 and 405.500. Floral visitors were only female bees of the families Anthophoridae (that collected oil and pollen), Apidae and Halictidae (that collected only pollen). Based on the strategies and rewards (oil and pollen), the high P/O ratio, and mainly because of the absence of fruits from self-pollination tests, it is concluded that this species is xenogamic.