Latin sapo—soap, as the bruised leaves of S. officinalis produce a lather.

Annual or perennial herbs with tough rootstocks. Flowers with sepals tubular, indistinctly 5-nerved. Petals 5 with narrowed bases as long as sepals, tip entire or notched. Stamens 10. Styles 2. Fruit a capsule opening by 4 teeth.

Very similar to, but differing from, Silene and Lychnis by having 2 (not 3 or 5) styles and a capsule with 4 (not 6 or 10) teeth. The commonly grown S. officinalis has characteristic 3-veined leaves.

About 25 mostly montane species from Europe, Asia and Africa.

Simmler (1910).

Source: Spencer, R. (1997). Caryophyllaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.