T: Tasmania, Penquite, R.Gunn 568; lecto: K, designated here by K.L.Wilson; iso: NSW6844.
Perennials, 60–120 cm tall; rhizome 3–5 mm in diam., forming large loose clumps. Stem leafless, terete, 1.5–3.5 (–5) mm diam., hard, various shades of green, pale, subglaucous; ridges 35–75, conspicuous; subepidermal sclerenchyma strands present, some connected to small vascular bundles; epidermis cells over the ridges radially enlarged; pith interrupted, of perfectly astericiform cells, often almost lacking in mature stems, or in high altitude forms continuous. Cataphylls 3–4; upper cataphylls 5–18 cm long, very lax, abaxially dull above, dark yellow-brown to red-brown and ±glossy at base, adaxially silvery or occasionally pale golden brown. Lower bract 8–18 cm long, exceeding inflorescence, with narrow sheath. Inflorescence pseudolateral, 2–6 (–14) cm long, diffuse or head-like; flowers (20–) 50–80, densely to loosely clustered. Bracteoles ovate, scarious. Tepals initially pale green, later stramineous-brown, occasionally tinged red-brown, with ±narrow membranous margins; outer tepals 2–2.5 (–3) mm long, longer than inner, acuminate-subulate; inner tepals acute. Stamens 3 (–6); anthers c. 0.5–0.7 mm long; filaments 0.4–0.6 mm long; style c. 0.1 mm long; stigmas c. 0.3–0.5 mm long. Capsule triseptate, ovoid to obovoid or ellipsoid, 2.3–3 mm long, shorter than or exceeding perianth, obtuse, not or shortly mucronate, golden or pale greenish brown. Seeds 0.35–0.4 × c. 0.2 mm, narrowly and obliquely ellipsoid, apiculate, pale brown, c. 16–22-striate, reticulate; appendages absent or reduced to pale apices.