Arrhenatherum elatius (L.) P.Beauv. ex J.Presl & C.Presl

Loosely tufted, coarse perennials, (40)–60–150 cm. Leaf-sheath ± chartaceous, smooth, or rarely minutely scabrid, sometimes with scattered long fine hairs. Ligule 1–3–(4) mm, truncate to ± obtuse, erose, ± ciliate, abaxially minutely scabrid to minutely hairy. Leaf-blade 15–30–(50) cm × 2–12 mm, minutely scabrid on ribs, to ± smooth, adaxially often with scattered long fine hairs; margins minutely, closely scabrid, tip acute, scabrid. Culm erect or ± spreading, stout. Panicle (4)–14–32 cm, erect or nodding, dense or lax, slender and lanceolate or with lower branches spreading; rachis smooth below, scabrid above, branches and pedicels slender, scabrid. Spikelets 7.5–9.5–(11) mm, shining, green or purplish. Glumes acute, sometimes finely scabrid, nerves finely scabrid; lower (3.5)–4.5–6–(6.8) mm, lanceolate, 1-nerved, upper ≤ spikelet, ovate-lanceolate, 3-nerved. Lemma (7)–8–9 mm, 7-nerved, ovate-lanceolate, hyaline near acute tip, nerves distinct, finely scabrid, upper or both lemmas with scattered fine hairs in lower ½; awn of lower lemma 8–16.5 mm; awn of upper lemma 0.5–10 mm, or 0. Palea narrower than lemma, keels finely ciliate, interkeel minutely scabrid, apex shortly bifid. Callus usually ringed by short stiff hairs. Rachilla prolongation 1.5–2.5 mm, delicate, glabrous. Anthers 3.5–5 mm. Gynoecium: ovary 0.6–0.8 mm; stigma-styles 1.5–1.8 mm. Caryopsis 2.5–3.8 × 0.8–1.2 mm.

[From: Edgar and Connor (2000) Flora of New Zealand. Volume 5 (second printing).]