Samolus valerandi is a species of semi-aquatic flowering plant in the primrose family, Primulaceae.

Its inflorescence is a raceme, with small white flowers on long stalks.

[10] Samolus valerandi is widely distributed across western and Mediterranean Europe, north Africa, Asia and Australia, Central and South America including Cuba, and Japan.

[11] This species is found in a variety of wet habitats, including stream banks, tidal marshes, and seeps.

[citation needed] The plant's leaves, when cut and agitated in water, produce a lather, for which reason in Palestine it has been used by the local Arab population, in former times, to launder clothes and was called by them sabūn 'arab (= Arab soap).