Soapwort (Bouncing Bet)

Saponaria officinalis

Caryophyllaceae (pinks, carnations)


Soapwort is a nonwoody perennial with simple or branched stems, often forming large colonies. Flowers are in tight or open groups (cymes), subtended by leafy bracts. The flowers are typical of the pink or carnation family: the sepals are fused to form a long, slender tube; petals 5, each with 1 rounded notch, white or pink, showy, with a delightful fragrance. Blooms June–October. Leaves opposite, elliptical to lance-shaped, hairless, to 8 inches long.


Height: about 2 feet.

Habitat and conservation

Occurs on banks of streams, rivers, and spring branches; also old fields, pastures, fencerows, old homesites, gardens, railroads, roadsides, and open, disturbed areas. Native of Eurasia, introduced worldwide. A familiar roadside wildflower, often forming large colonies that are difficult to eradicate, partly because of the toughness of the rhizomes. Cultivars with fancy forms and colors are common in gardens and may persist at old homesites.

image of Soapwort Bouncing Bet distribution map
Distribution in Missouri

Scattered to common nearly statewide; less abundant in northern counties.

Human connections

“Bouncing Bet” apparently is an antique English term for a vigorously scrubbing laundry woman (“Bet” being a nickname for “Elizabeth”). It and “soapwort” both describe this tall, showy wildflower, which has chemicals in its sap that lather up like soap. "Wort" is a word that means "herb" or "nonwoody plant."

This plant contains a mucilaginous juice that forms lather in water. In the past, the leaves were often used for soap.

The seeds contain the same saponin chemicals that cause the sap to lather up, and the seeds are poisonous.

Plants with "officinalis" in the scientific name usually had medicinal uses in the past.

Ecosystem connections

Although some butterflies and moths visit, soapwort's flowers aren't very attractive to insects. Mammals tend not to eat the foliage because of the toxic saponins in the sap. This plant is also weedy, even invasive in some areas. Where it outcompetes valuable native plants, soapwort is a problem.