BOUNCINGBET, Saponaria officinalis L. 1, lower part of plant; 2, flowering stems; 3, flower; 4, mature seed pod with part of calyx removed; 5, seed. Perennial, reproducing by seeds and short rhizomes. Stems stout, jointed, erect, 12 to 24 inches (30 to 60 cm) tall, clustered, smooth, and usually unbranched. Leaves opposite, smooth, entire, 2 to 3 inches (5 to 7.5 cm) long, about 1 inch (2.5 cm) wide, without petioles. Flowers in conspicuous clusters at the tops of the stems; about 1 inch (2.5 cm) across with 5 pink or white petals, and with base enclosed in a tubular calyx about 3/4 inch (1.9 cm) long. Seed pod narrowly egg-shaped, pointed, containing numerous seeds, enclosed by calyx. Seeds flattened, dull black, kidney-shaped, about 1/16 inch (1.5 mm) long, surface covered by curved rows of minute knobs. Found along roadsides, in waste places, and on ditch banks. Originally grown in gardens as an ornamental, from which it has spread. In pioneer days, used as a soap substitute, the stems and rhizomes making a foamy solution when bruised in water.