Yellow, with dull red centre.
Mostly south and west.
Flowers: axillary; on long peduncles. Calyx: of five green sepals, sharply pointed. Corolla: wheel-shaped; of five segments. Stamens: five. Pistil: one. Leaves: opposite; lanceolate; wavy on the edges. Stem: two to four feet high; upright; rather rough.
During the summer these pretty flowers may be found in the moist soil of thickets. It is owing to a close resemblance to the loosestrifes that their English name has been bestowed on them.
S. lanceolatum, or lance-leaved loosestrife, is a similar species. Its leaves are on petioles, or almost sessile, and from their axils arise the slender stalks that bear the flowers.