Silene latifolia subsp. alba (formerly Melandrium album), the white campion is a dioecious flowering plant in the family Caryophyllaceae, native to most of Europe, Western Asia and Northern Africa. It is a herbaceous annual, occasionally biennial or a short-lived perennial plant, growing to between 40–80 centimetres tall. It is also known in the US as bladder campion but should not be confused with Silene vulgaris, which is more generally called bladder campion.
The appearance depends on the age of the plant; when young they form a basal rosette of oval to lanceolate leaves 4–10 cm long, and when they get older, forked stems grow from these, with leaves in opposite pairs. The flowers grow in clusters at the tops of the stems, 2.5–3 cm diameter, with a distinctive inflated calyx and five white petals, each petal deeply notched; flowering lasts from late spring to early autumn. The entire plant is densely hairy. Occasional plants with pink flowers are usually hybrids with red campion (Silene dioica).()
