Saponaria

Saponaria is a genus of flowering plants in the family Caryophyllaceae. They are native to Europe and Asia, and are commonly known as soapworts.
They are herbaceous perennials and annuals, some with woody bases. The flowers are abundant, five-petalled and usually in shades of pink or white.
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. The genus name "Saponaria" derives from the Latin "sapo" ("soap") and -"aria" ("pertaining to"), and at least one species, "S. officinalis", has been used to make soap. It contains saponins, and a liquid soap could be produced by soaking the leaves in water. This soap is still used to clean delicate antique tapestries.
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. It is also related to "Gypsophila", but its calyx is cylindrical rather than bell-shaped.
"Saponaria" species are eaten by the larvae of some butterflies and moths, including the Lychnis and "Coleophora saponariella", which is exclusive to the genus.
Diversity.
There are 30 to 40 species in the genus.
Species include: