Erect, usually simple, aquatic herb, up to 300 mm tall. Stem leaves ovate, 10-50 mm long, lower leaves oblanceolate, 10-30 mm long. Lowermost flowers in inflorescence sessile and cleistogamous. Perfect flowers pedicellate, pedicels 5-10 mm long. Fruit globose or ovoid, 1.5-2.0 mm long. Flowers white or pale mauve.