Marsh Rabbits live only in marshy areas, and like Swamp Rabbits, are good swimmers. They are often found in habitats with pools of brackish water and plants such as cattails, water hyacinth, rush, centella, and marsh pennywort. They feed on all of these plants, and build nests of soft grass and fur in sedges at the edge of the water. Marsh Rabbits have relatively small litters of 2 or 3 after a gestation of about 30-37 days.

Links:
Mammal Species of the World
Click here for The American Society of Mammalogists species account