Extrafloral nectaries on <i>Cenchrus americanus</i> (L.) Morrone

Abstract Pearl millet, Cenchrus americanus (L.) Morrone (formerly Pennisetum glaucum L.), used for food and feed, has pollen that attracts multiple insect species. In 2023, honey bees and wasps were observed foraging on or below the auricles of pearl millet in a Georgia field. In 2025, pearl millet was grown in a greenhouse and found to be secreting extrafloral nectar. This extrafloral nectar was collected and found to be composed of sugars, primarily sucrose but also glucose and fructose, as well as protein. Nectar droplets were seen at the tips of the auricle hairs, on the culm, and on the leaf sheaths. Large amounts of extrafloral nectar accumulated just below the auricle. Magnification of hairs on the auricle revealed the presence of multicellular hairs with bulbous bases. We conjecture that these bulbous structures may function as extrafloral nectaries, which drip nectar from the auricle down onto the culm and leaf sheath. Thus, we report the discovery that pearl millet not only provides pollen for insects but also may provide nectar.