A unique growth pattern associated with cleistogamy in a tropical legume, Vigna minima (Roxb.) Ohwi & Ohashi (Leguminosae)

Obligate subterranean cleistogamy, observed in a natural population of Vigna minima , is associated with the production of one or two negatively geotropic, leafy shoots and several positively geotropic, highly pigmented, leafless shoots. The latter branch profusely after penetrating the soil and produce much reduced, cleistogamous flowers. The undehisced anthers contain germinated pollen grains. The seeds developing from the cleistogamous flowers differ in size, weight and surface features from those produced by the chasmogamous flowers of other natural populations within the species.