FLORAL BIOLOGY OF MYRISTICA-FRAGRANS HOUTT (MYRISTICACEAE), THE NUTMEG OF COMMERCE

The flowering and pollination of Myristica fragrans were studied on plants cultivated in southern India. The staminate flowers are borne in indeterminate inflorescences and function only for a single night. Pistillate flowers are borne solitarily and appear receptive for 2-3 days. Staminate plants may produce over 50 times as many flowers as pistillate plants. Both types of flowers are strongly fragrant. A single species of beetle, Formicomus braminus (Anthicidae, ant-mimicking flower beetles), appears to be the best candidate for an effective pollinator of nutmeg in the area of the study, although other species of small beetles may be involved. The beetles are strong fliers, are active nocturnally around staminate flowers, and carry significant pollen loads. Pollen is the only evident pollinator reward. Pistillate flowers produce no reward, and spatial constraints of the perianth and stigma appear to prevent beetles from entering the flowers. Pollen carried on the beetle''s head or body would be deposited on the stigma when the insect attempts to enter the flowers. Pollen carried on the beetle''s head or body would be deposited on the stigma when the insect attempts to enter the flower. This is the first report of a food-deception automimicry in a cantharophilous pollination system. The pollen/ovule ratio for M. fragrans is estimated to be 801,000/1, a very high P/O ratio for an insect-pollinated plant.