Single erect tuft or sparsely clumping perennial herb with fibrous roots. Narrow dark green leaves 10-25cm x 5-17mm on branching stems. Leaf sheath closely folded and fused. Irregularly minutely saw-toothed on margins and midrib on lower surface. Pale to dark blue flowers. Anthers yellow-brown, swollen stamen stalk yellow. Flowers to 20mm wide, petals and sepals spreading. Distinctive violet to purple anthers. Berries blue.