Cyperus longus L.

Rhizome far-extending, woody, branched, to 1 cm diam. Stems to 60 cm × 2.5 mm, 3-angled, leafy at base. Leaves slightly < stems, 2–3 mm wide, double-folded, margins smooth below, finely scabrid towards tip; basal sheaths white to red, with numerous deep reddish-brown nerves, upper sheaths white. Involucral bracts 3–4, leaf-like, unequal, lowermost exceedingly long (to 50 cm). Inflorescence a compound umbel; rays several, unequal, ± filiform, to 5 cm long. Spikelets reddish- to purplish-brown in digitate clusters, linear compressed, subacute, 6–11 × ± 2 mm. Rhachilla with delicate hyaline wings from base of glumes. Glumes 2.5–3 mm long, closely imbricate, ovate-lanceolate, obtuse, reddish-brown to reddish-purple except for bright green keel, shining, nerves obscure. Stamens 3. Style-branches 3. Nut ± ⅓ length of glume trigonous.

[From: Healy and Edgar (1980) Flora of New Zealand. Volume 3.]