Leymus arenarius (L.) Hochst.

Green- or blue-grey perennials, in thick tufts 60–140 cm, with long, strong rhizomes. Leaf-sheath glabrous, firmly chartaceous, shredding into fibres at maturity, cream to light brown, with chartaceous auricles to 3 mm. Ligule 0.6–1 mm, rim-like, obviously ciliate. Leaf-blade 12–75 cm × 6–12 mm, flat or involute, rigid, abaxially smooth, adaxially finely scabrid on ribs, long-narrowed to pungent tip. Culm 45–110 cm, erect or spreading, internodes glabrous. Spike 14–30 × 1.5–2 cm, stiff, erect, with paired spikelets appressed to rachis; rachis angled, margin finely hairy or glabrous. Spikelets 16–25 mm, 3–6-flowered, yellowish green. Glumes equal, ≈ spikelet, 3–5-nerved, narrow-lanceolate, rigid, abaxially with scattered fine hairs, especially on keel and towards margins near acuminate or mucronate tip, adaxially finely hairy. Lemma 13–20 mm in lower florets, upper lemmas shorter, 7-nerved, lanceolate, acuminate to mucronate, firm, abundantly silky-pubescent throughout. Palea ≈ lemma, folded, keels finely toothed, interkeel minutely silky-pubescent near apex, membranous margins of flanks contiguous, conspicuously short hairy; adaxially hairy, shortly ciliate at notched apex. Callus 0.5 mm, bearded with long hairs. Rachilla 3.5–4 mm, abundantly silky-pubescent. Lodicules 2.5–2.75 mm, ciliate. Anthers 6–7.2 mm. Gynoecium: ovary 1.5–2 mm, orange-brown, hair covered; stigma-styles 2.8–3.5 mm. Caryopsis 7–9 × 2–2.5 mm.

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