Avena L.

Annuals or biennials, with solitary culms or tufted. Leaf-sheath chartaceous, striate, rounded. Ligule membranous. Auricles 0. Leaf-blade flat, rarely convolute. Panicle loose to sometimes contracted or secund with large nodding spikelets. Spikelets with 1–6 ☿ florets and 1–(2) ♂ or rudimentary florets; disarticulation below each floret, or only above glumes, or not at all in cultivated spp.; rachilla prolonged. Glumes usually equal and equalling spikelet, 3–11-nerved, rounded, lanceolate, acuminate, herbaceous to thinly chartaceous with thick scarious margins. Lemma usually coriaceous at maturity, bidentate to biaristulate and then rarely with 2 additional setae, rarely subentire; awn middorsal, stout and geniculate, column usually twisted, cultivated spp. often with reduced awns or awnless. Palea tough, ≤ lemma, 2-keeled, keels ciliate. Lodicules 2, linear-lanceolate, or unequally bilobed or with a rudimentary side-lobe. Callus hairy or glabrous. Stamens 3. Ovary hairy; styles free. Caryopsis terete, grooved; embryo relatively small to very large; hilum linear; endosperm solid.

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