Flax lily is the common name for the flowering plants of the scientific genus Dianella. The flax lily is a perennial, found from Japan to India, south to Australia and New Zealand, and in many of the Pacific Islands. More than half of the species in the genus are found in Australia. The number of species in the genus is disputed, but estimates range from 20 to more than 30.
Originally in the family Hemerocallidaceae, flax lilies are now in the family Xanthorrhoeaceae. Found in forests, rainforests, and on coastal dunes, the flax lily has long leaves that can grow up to 3 feet (1 m) long and that come in colors from deep to pale green. The foliage is grass-like in appearance and is often variegated with creamy white. The flax lily produces an underground rhizome and is a monocot plant that can grow up to 5 feet (1.5 meters) in height.
The flax lily produces blue, white, or violet star-shaped flowers in the spring. The flowers have three petals, three sepals, and a large, yellow stamen. In most species the flowers are above the leaves and in sprays at the end of the stem.
Showy, shiny blue or purple berries are produced after flowering. The shape of the berries ranges from spherical to elongated, depending on the species. The berries have a spongy pulp and shiny black seeds.
Some species are cultivated for their foliage and berries. When cultivated, flax lily is frost hardy and grows best in full sun to partial shade. Propagation is by division of the rhizome or can be from seed. The most commonly cultivated species are D. coerulea, D. intermedia, and D. laevis.
The plant is susceptible to pests, including whitefly, scale, and spider mites. It should be grown in soil that is kept evenly moist. Warm water should be used, and water that is too acidic can be damaging. Once it is established, the plant is drought tolerant.
Some species are used in landscaping, and others produce an edible fruit, though the fruit of some species is poisonous. The Australian aborigines used the leaves of the plant to weave dillies, a traditional bag. The Ngarrindjeri, a tribe of Tasmania, chewed the root of Dianella as a medication for colds. Some species of the plant are grown as house plants in areas where it is not hardy.