Most of the research i've found on that issue (really wet soils) is to use american jointvetch(aeschynomene). It has been proven to last under stands of water for prolonged periods. This is only a warm season annual though.
If you wanted clover,....... durana clover was proven to last under water for 10 days. This is more than any other variety of white clover tested. The only wet soil mix i have for clovers is 6 lbs durana white, 10 lbs crimson clover, and 50 lbs annual rye. This would be a fall planting.
Hope that helped,......