Male-biased sex ratio and promiscuous pollination in the dioecious island treeLaurus azorica (Lauraceae)

Pollination ofLaurus azorica (Lauraceae), a dioecious Macaronesian tree, was studied. Male and female trees had the same size distribution. The population had 2.5 times as many male trees as females. In addition, males produced more flowers, and their inflorescences lasted longer. Individual flower lifetime and length of flowering season were the same in both sexes. Between the years of observation, one tree changed sex. Pollinators wereHalictinae bees and the flyTachina canariensis. The bees collected pollen and nectar and the fly collected nectar from both sexes. Both species visited other plants as well. The evolution of breeding systems inLauraceae is discussed.