Data on pollination ecology of Araceae are still scarce and most concern species belonging to the subfamily Aroideae (García-Robledo et al. 2004, Gibernau 2003, Ivancic et al. 2004, 2005; Maia & Schlindwein 2006). In this subfamily, inflorescences consist of unisexual flowers: female flowers are located in the lower portion and the male flowers are in the upper portion of the inflorescence (Mayo et al. 1997). In the documented neotropical Aroideae, pollinators are nocturnal beetles and pollination mechanisms take place within a floral chamber during a short flowering cycle (generally 24– 48 h) with floral rewards (sterile flowers rich in proteins and/or lipids) for the beetle pollinators, the secretion of resin to secure pollen on the pollinator, and the production of heat and odours (Chouteau et al. 2007, García-Robledo et al. 2004, Gibernau & Barabé 2002, Gibernau et al. 1999, 2000, 2003; Maia & Schlindwein 2006, Young 1986). However, the pollination ecology of the neotropical genera bearing bisexual flowers is poorly known and is mostly based on observations and a few studies (Croat 1980, Franz 2007, Kraemer & Schmitt 1999, Montalvo & Ackerman 1986, Ramirez & Gomez 1978, Schwerdtfeger et al. 2002). The bisexual flowers generally consist of a whorl of stamens surrounding a pistil, with (e.g. Anthurium) or without (e.g. Monstera) a perianth (Mayo et al. 1997) and in some species a basal sterile zone is present (e.g. Monstera). In the documented species (i.e. Anthurium, Spathiphyllum) pollination mechanisms appear relatively simple (a long flowering cycle, the lack of a floral chamber), pollinators are believed to be diurnal bees and thermogenesis has never been documented. The genus Monstera, ubiquitous throughout the neotropical 1 Corresponding author.