Saponaria is a genus of flowering plants in the family Caryophyllaceae. They are native to Europe and Asia, and are commonly known as soapworts.[1]
They are herbaceous perennials and annuals, some with woody bases. The flowers are abundant, five-petalled and usually in shades of pink[2] or white.[1]
The most familiar species might be common soapwort (S. officinalis), which is native to Eurasia but is known in much of the world as an introduced species, often a weed, and sometimes a cultivated ornamental plant.[1] The genus name Saponaria derives from the Latin sapo (“soap”) and –aria (“pertaining to”),[1] and at least one species, S. officinalis, has been used to make soap.[3] It contains saponins, and a liquid soap could be produced by soaking the leaves in water.[1] This soap is still used to clean delicate antique tapestries.[4]
The genus is closely related to Lychnis and Silene, being distinguished from these by having only two (not three or five) styles in the flower.[2] It is also related to Gypsophila, but its calyx is cylindrical rather than bell-shaped.[5]
Saponaria species are eaten by the larvae of some butterflies and moths, including the Lychnis and Coleophora saponariella, which is exclusive to the genus.