Family, Figwort. Color, deep yellow. Calyx-divisions toothed, leaf-like. Corolla of the snapdragon type, the upper lip 2-cleft, the under 3-lobed. There are 2 perfect and 2 sterile stamens. 2 bracts under the calyx. Leaves, ovate or oblong, broad at base where they clasp the branches, serrate at apex. Flowers, in the leaf-axils of the smooth, delicate, weak branches which grow upright from creeping stems, 6 to 18 inches long. June to September.
A bright, pretty plant, growing in mats or tufts on the edges of Long Island fresh-water bays, and on banks of brooks, often quite in water, blossoming all summer. Swamps or wet, sandy shores from Maine to Virginia and westward.