2n = 18

Slender, upright to sprawling dioecious perennial, 0.6-1 .8(-2 .5) m tall, forming dense somewhat flaccid rafts on peat an d peaty soils. Rhizome 3-10 mm diam., horizontal, sparingly branched, covered with tightly appressed, overlapping scales; scales 3-12 × 2-12 mm, broadly ovate to ± deltoid, chartaceous, dark brown, lustrous, nerves indistinct, apex rounded and mucronate. Roots 3-4 mm diam., 5-12 cm long, grey, drying to tan, soft, spongy, with few (if any) rootlets. Culms up to 2 m long, 1-5 mm diam., gradually tapering toward distal end, firm, flexuose, slender, terete, smooth, dark green-brown to brown, often blotched black; branched in upper 2/3, branches numerous, firm, flexuose, scrambling, terete; basal 50-65 mm of culm slightly swollen with soft, spongy, light brown tissue; pith absent, with 3 hollow triangular segments, these deteriorating to a ± circular cavity. Culm base with 3-7 loosely appressed, overlappin g scales; scales 8-25 × 10-12 mm, ovate to narrowly ovate, coriaceous, light brown to brown, nerves distinct, apex rounded and mucronate. Leaves along culm solitary, distant, gradually smaller toward distal end; lamina 15-30 × 6-11 mm, narrowly ovate, chartaceous, tan, brown to grey-brown, appressed to and sheathing culm, nerves distinct; margins entire to praemorse, sometimes cream; apex rounded, with mucro up to 8 mm long. Inflorescence a terminal panicle, often with cymose branching near base, 30- 150(-200) mm long, dark dull brown, upright to spreading; male and female inflorescences sparse, not crowded; flowers subtended by 2 bractlets, 2 bractlets subtended by 1 bract; inflorescenc e branchlets subtended by reduced leaves. Bracts 5.5- 10.0 × 2.6-3.0 mm, ovate, narrowly ovate to lanceolate, light brown, membranous, apex acuminate, margins fimbriate. Bractlets 5.2-5.8 × 1.0-1.6 mm, lanceolate, membranous, light brown to yellow brown, apex acuminate, margins entire. Flowers pedicellate to almost sessile. Tepals 6, in 2 whorls of 3, 4.0-6.0 × 1.0-1.2 mm, lanceolate, light brown, channelled, keeled, apex strongly acuminate. Stipe 0.3-0.4 mm long. Male flowers with 3 stamens; filaments 1.6-3.0 mm long, anthers 1.8-2.3 mm long, cream, unilocular, medifixed, pollen yellow; pistil rudimentary. Female flowers with 1 pistil; style 1.0- 1.5 mm long, pale orange, papillose on adaxial surface; ovary 0.6-0.7 × 0.3-0.4 mm, ellipsoid, brown to light brown, glossy; staminodes 3, each 1.5- 1.6 mm long. Fruit 3.0-3.5 × 1.0-1.2 mm, oblongellipsoid, light brown to brown, sutures not prominent, surmounted by persistent short style; indehiscent. Seed 1.2–1.5 × 0.9–1.0 mm, oblong to broadly ovate, dark brown; testa membranous; surface bireticulate, primary pattern prominent with rectangular to rectangular-polygonal, ridges c. 1 mm wide, secondary pattern prominent, irregular, ridges 5–7 mm wide, endosperm white. Chromosome number 2n = 18 (Murray & de Lange 1999 (fig. 1J); AK 235305).

Extremely robust, 1–2–(3) m. high. Rhizome 0.6–1 cm. diam., horizontal, covered with tightly appressed, overlapping, pale chestnut, papery scales. Roots thick and matted, 2–5 mm. diam. Culms simple below, 3–10 mm. diam., upper ⅔ much more slender, narrowly branched, branches stiff but flexible, smooth. Lvs reduced to acuminate sheaths, distant, closely appressed to the culm, c. (2)–3–(4) cm. long below, gradually smaller above; margins of sheaths at lowermost nodes split to form a fringe. Plants dioec. Infl. a terminal, cymose panicle, bracts subtending branchlets red-brown, acuminate, with membr. margins, each fl. enclosed by a rigid lanceolate bract. Fls pedicellate or almost sessile, each with 2 hyaline bractlets at the base. Tepals 6, lanceolate, acute, yellow-brown. ♂ with 3 stamens; anthers ⅔ length of tepals; filaments very short; ovary rud. ♀ with 3 slender staminodia, anthers aborted; style densely papillate along its whole length; ovule 1. Fr. c. 1 mm. long, slightly < 1 mm. wide, 2-sided with angles very much thickened, surmounted by a hard, thickened style-base c. 1 mm. long; dehiscing along one edge only. Seed c. 1 × 0.5 mm., oblong, brown, surface minutely reticulate.