Emphasis on use of moist-soil management for waterfowl has increased in recent years. One component of this form of management which is not well documented are seed yields of many native plants produced. Seed yields of 4 moistsoil plant species were measured during the growing season of 1985 and 1986 on the Noxubee National Wildlife Refuge in Mississippi. Seed yields of 3 species, Polygonum hydropiperoides (Michaux), Polygonum densiflorum (Meissner), and Rhyncospora corniculata (Gray), were measured using a specially designed seed trap. The fourth species, Ludwigia glandulosa (Walter), was measured by clipping plants from 0.31-m2 quadrats, then removing their capsules. Of the 4 species measured, P. densiflorum and R. corniculata appeared to be the best overall seed producers, producing an average of 430 kg/ha and 661 kg/ha in 1985, respectively, and 576 kg/ha and 1,091 kg/ha in 1986, respectively. P. hydropiperoides produced much less seed than P. densiflorum, with an average of 85 kg/ha in 1985 and 21 kg/ha in 1986. Possible waterfowl use of L. glandulosa seed was determined by observing birds feeding on 12 days in areas containing driftlines composed predominantly of its seed and by collecting 8 birds from the same areas and analyzing their proventriculi and gizzards. Though L. glandulosa was the highest seed producer studied, with an average of 946 kg/ha in 1985 and 907 kg/ha in 1986, it was not a selected waterfowl food.