Soapwort (Saponaria officinalis) is a vespertine flower, and a common perennial plant from the carnation family (Caryophyllaceae). Other common names are Bouncing Bet and Sweet William. The scientific name Saponaria is derived from the Latin sapo (stem sapon-) meaning "soap," which, like its common name, refers to its utility in cleaning. From this same Latin word is derived the name of the toxic substance saponin, contained in the roots. It starts producing a lather when in contact with water.… (More on Soapwort)