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Abstract

Floral biology of Schinus terebinthifolius Raddi (Anacardiaceae) in sandbank areas of Santa Catarina Island, Brazil. Schinus terebinthifolius Raddi is a brazilian native dioecious species of Anacardiaceae with a wide geographical distribution and great ecological plasticity. The study was carried out in a sandbank area, in the municipal district of Florianópolis — SC, from September 2002 to May 2003. Analysis of the flower morphology of both sexes, measures of the inflorescence lengths and widths, counting of the inflorescence numbers per branch and flowers per inflorescence, as well as the daily number of opened flowers, were all performed with the aim of detecting a probable reproductive dimorphism. The results obtained in the present study demonstrate that the studied plant present diclinous flowers, depending basically on insects for pollination. Anthesis occurs always in the morning and the male flower has a duration of only 12 hours, while the female flower remains receptive for a period of more than 32 hours. In the 1st reproductive period of the study (springtime), just 22% of the plants were blooming. In the 2nd period (summer/autumn), 100% of the individuals were blooming. The species presented sexual dimorphism, manifested by the length (t= -12.75; p<0.5) and width (t= -11.78; p<0.5) of their inflorescence. However, the similarities between their flowers, added to the synchrony of their reproductive period, the anthesis and availability of nectar, in both sexes, seem to attenuate the differences and possibly favor reproductive success through the attraction of floral visitors to both types of flower.