Biologia floral e visitantes de gaylussacia brasiliensis (spr.) meissner (ericaceae) - Uma espécie com anteras poricidas polinizada por beija-flores

Abstract

The floral biology of Gaylussacia brasiliensis (Spr.) Meissner (Ericaceae) was studied on swampy edges of a gallery forest in Uberlandia, Minas Gerais. Gaylussacia brasiliensis is a shrub 0.3 to 3.0 m tall that occurs isolated or aggregated and has continuous flowering. The axillary racemose inflorescences produce four to dozens of pendulous flowers. The flowers are hermaphroditic, red, urceolate, odorless and have diurnal anthesis. Concentration of sugars in nectar was c. 13% and volume c. 3.0 μL. G. brasiliensis is a self-compatible, non apomictic species, which does not present spontaneous self-pollination. The pollinators of G. brasiliensis were the hummingbirds: Chlorostlibon lucidus (Shaw), Amazilia fimbirata (Gmelin), Hylocharis chrysura (Shaw) (Trochilinae) and Phaethornis pretrei (Lesson & DeLattre) (Phaethornithinae). G. brasiliensis has poricidal anthers wiample pores and the hummingbirds, while hovering withe bill inserted into the flowers to search for nectar, promote enough vibration in the anthers to permit pollen-grain release. Although presenting relatively low nectar volume and sugar content, the clusters of individuals wimany flowers seem to attract territorial hummingbirds.