Flower Scent and Pollination in Selected Neotropical Palms

Abstract: The flower scents of 14 palm species were collected in the field in Ecuador and Puerto Rico by head‐space adsorption and analysed by gas chromatography‐mass spectrometry. Insect visitors were recorded in seven of the species in Ecuador. The floral scent of the different species was dominated by a variety of compounds, e.g., the fatty‐acid derived 3‐pentanone and the hydrocarbon series dodecane to pentadecane, the benzenoid compound 1,4‐dimethoxybenzene, the isoprenoids ( E )‐ocimene, myrcene, linalool, and ( E )‐α‐farnesene and the nitrogen‐containing compound 2‐methoxy‐ sec ‐butylpyrazine. Rather than mirroring the systematics of the studied palm species, the chemical composition of the floral scent reflected the pollination mode. The scent of beetle‐pollinated species was characterized by large amounts of one or a few dominant compounds, whereas fly‐ and bee‐pollinated species contained a mixture of several compounds in smaller total amounts. We suggest that specific scent compounds, as found in the beetle‐pollinated species, have evolved as a response to pollinator preferences. The importance of olfactory cues in relation to visual cues is higher in beetle‐pollinated species than in species pollinated by flies and bees.