Monomorphism, reduced gene flow, and cleistogamy in rare and common species of Lespedeza (Fabaceae)

Population genetic structure was analyzed in the rare, native prairie legume Lespedeza leptostachya and in the widespread L. capitata. Both species produce a mixture of chasmogamous and cleistogamous flowers. L. leptostachya is entirely monomorphic at all loci studied, while L. capitata shows strong among-population differentiation for the limited variation that occurs in that species. Allozyme data suggest that the level of gene flow among populations of L. capitata is very low, and that very low levels of outcrossing are effected by the chasmogamous flowers in L. capitata. -from Authors