Ricinis communis castorbean. Tropical tree grown as an annual, native to India and tropical Africa. The source of castor oil, known for its medicinal use as a purgative, it also has the property of dispersing completely in water and does not leave a ring. It is widely used in bath oils and soaps to soften and lubricate the skin. Castor oil is also an ingredient in paint, varnish, plastics and lubricants.
Seeds are highly poisonous if eaten.
Saponaria officinalis soapwort. Hardy perennial native to Europe. This plant was named for its high level of saponins, a term applied to a wide range of organic compounds which produce soapy, frothy solutions when rubbed or boiled in water. Saponins derived from other plant sources account for the frothy 'head' on beer and softdrinks. Soapwort was once widely used in Europe, as soap was rare and costly.