The reproductive phenology of eight medicinal plants in Omo Biosphere Reserve, Nigeria, was monitored monthly for twenty-four months. The flowering and fruiting periods of the species were cyclic. Dioscoreophyllum cumminsii, Irvingia gabonensis, and Xylopia aethiopica had well defined, predictable reproductive periods each year, while Carpolobia lutea, Sphenocentrum jollyannum, and Spondias mombin flowered and bore fruit either irregularly or continuously throughout the year. It is argued that while the ecological harvesting and sustainable management of Dioscoreophyllum cumminsii, Irvingia gabonensis, and Xylopia aethiopica would be easy, the reverse would be the case for Carpolopia lutea, Sphenocentrum jollyannum, and Spondias mombin.
Keywords: phenology, medicinal plants, ecological harvesting, sustainable management, Nigeria.