Avena fatua L.

Tall, green or light green tufts to 1.5 m, robust, or sometimes with rather slender culms. Leaf-sheath slightly hairy, upper sheaths glabrous. Ligule 2–7 mm, truncate to oblong and obtuse, denticulate, abaxially scabrid. Leaf-blade 15–50 cm × 4–15 mm, scabrid on ribs and margins, often with scattered hairs, especially on margins. Culm erect or occasionally geniculate at base, internodes glabrous. Panicle (15)–20–38 cm, lax, equilateral, ± nodding; branches widely spreading, slender, drooping, scabrid. Spikelets 35–50 mm, 2–3-flowered, pendulous on fine unequal pedicels; disarticulation below each floret at maturity. Glumes 9–11-nerved. Lemma 15–17.5 mm, narrow-lanceolate, light brown at first becoming tough and darker brown at maturity, stiffly hairy below level of awn insertion, or sometimes glabrous, scabrid on nerves above, narrowed to bidentate scarious apex; awn 30–40 mm, geniculate, stout, column dark brown, twisted. Palea keels with one row of cilia, interkeel scabrid. Callus with horse-shoe shaped scar densely bordered by long hairs. Anthers 2.5–3.5–(4) mm. Caryopsis 6–8 × 1.8–2.2 mm, light grey, densely hairy.

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