Perennial herbs, with a tuberous or bulbous or creeping rhizome. Leaves usually all radical, narrow, equitant and distichous. Flowers hermaphrodite, regular or obliquely irregular, solitary and terminal, or in spikes or corymbs or panicles, or clustered, enclosed within 2 spathaceous usually scarious bracts. Perianth superior, petaloicl, marcescent; segments 6, in 2 series, imbricate. Stamens 3, epigynous or inserted on the outer perianth-segments; filaments free or united into a tube; anthers 2-celled, opening outwards. Ovary inferior, 3-celled; style filiform, usually 3-fid above; divisions stigmatic at the end, subulate or narrow or broad, sometimes petaloid; ovules numerous, in the inner angle of each cell, anatropous. Fruit a coriaceous 3-celled usually trigonous capsule, loculicidally 3-valved. Seeds usually numerous, albu-minous; embryo short, cylindric.

A large order, comprising nearly 60 genera and about 700 species, dispersed over the whole world, but most abundant and varied in South Africa, plentiful in South Europe, not infrequent in America, comparatively rare in Asia. The order includes few useful species. Some are said to be purgative and diuretic, and the dried stigmas of the saffron (Crocus sativus) are a well-known dye. Many of the species are cultivated in gardens on account of the beauty of their flowers, especially of the genera Iris, Crocus, Ixia, and Gladiolus. The single New Zealand genus extends to Australia on the one side, and South America on the other.