Dietes grandiflora is a perennial, evergreen plant which grows up to 1.5m in large clumps. The plants grow from underground rhizomes.The long, rigid, sword-shaped leaves, held in a fan shape, are dark green and may reach up to 1m long and 15-20mm wide.The attractive flowers, held on erect slender stems about 1m in length, are large (about 100mm across) and are white with yellow nectar guides and outer tepals and violet central segments.
The flowers are borne in mass at certain periods — often after rain in summer. The individual flowers do not last more than a couple of days (so are of no use in a vase) however, the plant bears so many flowers during the peak period that the plant looks most striking. This plant is occasionally called the "Fairy Iris" because the fragile white petals not only look like fairy wings, but also have a tendency to disappear mysteriously overnight! The large wild iris fruit is a large capsule up to 45mm which is held erect and splits open to release shiny, dark brown seeds.
