M. myrtilloides ssp. parvifolia (Bentham) Morley, a neotropical melastome, was observed on Barro Colorado Island in Panama and found to be buzz-pollinated by female bees (Euglossa spp., Paratetrapedia sp.) and pollen-scavenged by other bees (Trigona spp.). The intrafloral behavior was examined for all bees and floral visitations were timed. Mouriri has long, exserted stamens and bears a concave oil gland. The secretory nature of this gland was confirmed by light and electron microscopy. The oil secretion was field-collected and its components analyzed by gas chromatography/mass spectroscopy and found to contain: at least 13 fatty acids (including methyl stearate and 12-methyltetradecanoate, glucose, amino acids (proline, alanine, glycine), carotenoids, a phenolic glycoside and possibly unidentified saponins). Females of the bee P. calcarata were observed to vibrate the anthers for pollen and to scrape at the elaiophors with modified fore-tarsal setae to collect the lipoidal mixture. Presumably, the floral oils are collected and used admixed with pollen as proteinaceous food in larval provisions, as has been demonstrated for the genus Centris. On the basis of the presence of anther elaiophors in Mouriri, Votomita and Memecylon, it is suggessed that the entire tribe Memecyleae should now be considered true oil-producing flowers. This is the 1st record of floral oil production and utilization by bees in the plant family Melastomataceae. The syndrome of oil flowers and oil-collecting bees is also briefly reviewed.