Fortnight lily
Formerly classified in the genus Moraea, and is still called morea iris by some gardeners. These are evergreen perennials with spreading fans of stiff, leathery sword shaped leaves up to 2 ft (0.6 m) in length but only 0.75 in (1.9 cm) wide. The upright clumps of leaves are held in a vertical fanlike plane and they spread on creeping rhizomes which sometimes ascend a few inches. The 2-4 ft (0.6-1.2 m) flowering stalks, which are perennial, are branched and stiffly wiry, bearing a succession of short-lived irislike flowers throughout spring and summer.
The flowers, rather flattened and nearly 3 in (7.6 cm) across, are milky white with yellow markings on the three larger tepals. (The three petals and three similar sepals of iris flowers are collectively called tepals.) Fortnight lily fruits are 1-2 in (2.5-5.1 cm) football shaped, three-sided capsules.
The fortnight lilies are often grown in borders because the narrow leaves are evergreen, and provide a strong vertical element. They're good along foundations, too. Fortnight lilies eventually form dense fan shaped clumps of leaves, and make a dramatic ground cover under large, tall trees. The flowers are beautiful, and although each lasts only a day, they are produced in profusion over an extended period from spring until late summer. They usually come in bursts, with a fortnight (two weeks) of rest between flowering events. Fortnight lilies seem to perform best in the light dappled shade of tall, open trees.
