Plants of this genus are evergreen perennial herbs growing from large, fibrous-coated corms. The lowest two or three leaves are cataphylls that sheath the lower stem and become dry. The thin, wiry, branching stem may bend and droop when in flower. It is lined with leaves that have linear blades with thick longitudinal veins and often no midrib. The inflorescence is a panicle of several spikes of flowers. The spikes may hang like bells or grow erect. The bracts around the flowers are usually dry, thin, membranous, translucent, and streaked or veined with brown. The bell-shaped flowers of most wild species are pink; red, purple, yellow, and white taxa also exist. There are many cultivars in a range of colors, sometimes with spots of yellow or blue. The fruit is a spherical capsule.