Tufts 1 cm to more than 1 m across at base. Aerial stems at first herbaceous and often flowering when less than 30 cm high, shrub-like in later seasons and to 1.5 m high, usually with many leafy extravaginal branchlets. Leaves 1-20 cm long, 0.5-15 mm wide; base sheathing, cylindrical for 0.1-3 cm, equitant above. Lower bracts ovate, amplexicaul, 1-6.5 cm long; upper bracts when present linear-subulate, 0.8-7 mm long. Perianth deep blue, pale blue or white; segments ±narrowly elliptic, 8-16 mm long, usually 5-nerved. Stamens to c. 10 mm long; anthers 1-2 mm long before coiling. Ovary c. 1.2 mm long; style 3-5 mm long. Capsule obovoid-triquetrous, 3-12 mm long, dull black. Seeds 1.5-3 mm long, 3-8 per locule.