It is an evergreen herbaceous perennial plant forming dense stands, spreading by way of its creeping rhizome, which is sometimes above ground, sometimes underground. Its stiff leaves grow vertically from a basal rosette. It is tough, durable and highly tolerant of low light and poor soil conditions. The tall, narrow, sturdy leaves are stiff and pointed. Colors include dark green, pale green, green edged with yellow, and variegated light green and yellow. Some species send up delicate flower spikes.