Swamp loosestrife is a sprawling, woody herb that grows in swamps and swampy shores of streams and ponds. It occurs in north and central Florida. Swamp loosestrife flowers in the late summer and fall.
This emersed plant is smallish and shrubby. Its lower stem is woody. Its upper stems are herbaceous. Swamp loosestrife leaves are opposite or in whorls of 3. Leaves are connected to the stem by short stalks. Its long leaves are lance-shaped with pointed tips. Typically they are 6 inches long and 2 inches wide. Swamp loosestrife flowers have short stalks and are purplish-pink with 5 to 7 petals. Flowers are about 1 inch across. Flower clusters occur at the leaf axles where the leaf meets the stem.