Friday, May 20, 2011
Beargrass in flower
Beargrass (Yucca filamentosa) is now in flower in dry open woodlands, on rock outcrops, and along roadsides in the piedmont and mountains. For fruits to form, this plant requires the pollination services of a tiny moth (the Yucca moth). Unlike all but a few pollinators, the Yucca moth intentionally pollinates the flowers. After pollinating a flower, a female moth lays eggs in the ovary, the larvae hatch, and then feed on the developing seeds. Usually about 30 % of the developing seeds are eaten. In this plant-insect mutualism, the flowers get pollinated and the moth is rewarded not by pollen or by nectar (the usual floral rewards) but by seeds for its larvae. Look for the tiny cream-colored moths hanging out in the flowers during the day.