It is a wetland plant in many habitat types. It is a rhizomatous perennial herb that forms clumps of stems 20 to 60 centimeters tall. The flat but curved leaves are located mainly at the base of the stems and are variable in length. The inflorescence is a matrix of many rounded racemes of many flowers each. Each flower has several dark brown to black tepals a few millimeters long and usually three small stamens enclosed between them. The fruit is an oblong capsule with a small beak at the tip.