Reproductive Biology of the Palm Acrocomia aculeata in Central Brazil

Phenology, floral biology, the reproductive system, and pollination of the macauba palm, Acrocomia aculeata were studied in Central Brazil. The species is arborescent, single-stemmed, and reaches heights of up to 16 m. Flowering occurs between August and December, peaking between October and November. Fruit fall (harvest) is between June and March, with a peak in November. Inflorescences are androgynous with marked protogyny. The basic pollination syndrome is by beetles, with wind playing a secondary role. The principal pollinators are Andranthobius sp. (Curculionidae), Mystrops cf mexicana (Nitidulidae) and Cyclocephala forsteri (Scarabaeidae). Cross-pollination between different individuals (xenogamy) accounts for most of the reproductive system. However, the species is self-compatible, with geitonogamy accounting for a significant percentage of fruit set. The combination of two pollination strategies (wind and insects) with a flexible reproductive system (crossand self-pollination) suggests that A. aculeata can be highly successful in the colonization of new areas, as is evidenced by the ample distribution of species in the Neotropics.