Avena sterilis L.

Strong, rather stiff, erect green tufts to 150 cm, with heavy panicles. Leaf-sheath glabrous, or rarely with scattered soft hairs. Ligule 3–8 mm, truncate, or more tapered centrally, shortly denticulate, finely ciliate. Leaf-blade 15–45 cm × 3–15 mm, very finely scabrid on ribs, adaxially sometimes smooth, rarely with scattered hairs; margins minutely scabrid. Culm internodes glabrous. Panicle 20–40 cm, equilateral, lax; rachis smooth, branches few, widely spreading, filiform, scabrid. Spikelets often drooping; disarticulation above glumes; rachilla tough and continuous between florets. Glumes 9–11-nerved. Lemma elliptic-lanceolate, tough and hairy below level of awn insertion, greenish above and scabrid on nerves, narrowed to scarious bidentate apex; lower 1–2 lemmas awned; awn geniculate, column red-brown, twisted. Palea keels with 1–3 rows of cilia, interkeel usually minutely hairy above. Callus bordered by dense short hairs.

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