1. Saponaria officinalis L. (bouncing-bet, soapwort)

Map 1478, Pl. 345 d, e

Plants perennial, colonial from long-creeping, branched rhizomes. Stems 30–90 cm long, erect or ascending, occasionally from a spreading base, unbranched or branched, glabrous. Leaves opposite, fused basally into a sheath, sessile or with a poorly differentiated, winged petiole to 1.5 cm long, lacking axillary clusters of leaves. Stipules absent. Leaf blades 3–11(–15) cm long, elliptic to ovate or oblanceolate, not fleshy, tapered at the base, rounded or angled to a bluntly or sharply pointed tip. Flowers in dense terminal clusters (those on short lateral branches sometimes appearing axillary), the stalks 0.1–0.5 cm long, erect to spreading at flowering and fruiting, the bracts paired and resembling small leaves. Epicalyx absent. Sepals 5, 15–20 mm long, becoming elongated to 25 mm long at fruiting, fused basally into a slender tube, this 15–25-nerved, herbaceous and green or reddish-tinged between the sepals, the lobes narrowly triangular, shorter than the tube, angled or tapered to a sharply pointed tip, not appearing hooded or awned, the margins papery and white. Petals 5 (rarely 10 or more in doubled horticultural forms), showy, 23–35 mm long, oblanceolate to spatulate, tapered to a stalklike base and this more or less fused to the ovary stalk, the expanded portion 0.8–1.5 cm long, rounded to shallowly notched at the tip, pink to white, with a pair of small appendages on the upper surface at the base of the expanded, spreading apical portion. Stamens 10, the filaments fused at the base. Staminodes absent (present in some horticultural forms). Pistil with 1 locule, the ovary with a stalk 2–5 mm long. Styles 2(3), distinct, each with a stigmatic area along the inner surface. Fruits capsules, 15–20 mm long, opening by 4(6) ascending to recurved teeth. Seeds mostly 30–75, 1.6–2.0 mm wide, kidney-shaped, the surface with minute, broad papillae or appearing pebbled, dark brown, lacking wings or appendages. 2n=28. June–October.

Introduced, scattered to common nearly throughout the state, but less abundant in the northern counties (native of Europe, Asia; introduced throughout the U.S., Canada, Mexico, Central America, South America, Africa, Australia.). Banks of streams, rivers, and spring branches; also old fields, pastures, fencerows, old homesites, gardens, railroads, roadsides, and open, disturbed areas.

Saponaria officinalis is a familiar nonnative roadside wildflower in most of the state. It often forms large colonies that are difficult to eradicate. The plants have tough rhizomes from which many flowering stems arise; new plants can easily arise from small portions of a rhizome. Several cultivars, including ones with doubled petals, staminodes replacing the stamens, and dark pink flowers, are commonly grown in gardens; they may persist at old homesites. The scientific name refers to the high concentration of saponins in the plant; the leaves often were used as a source for soap. The seeds of Saponaria also contain saponins and are poisonous (Burrows and Tyrl, 2001).