Avena* L.,. Sp. Pl. 79 (1753).

The old Latin name for oats.

revisions, nomenclatural references:
. B.R.Baum, A monograph of the genus

Key references
(keys and floras):
. G.Bentham, Flora Australiensis 7: 588(1878);
C.A.Gardner, Flora of Western Australia 1 Gramineae 36–37 (1952);
M.Lazarides, Flora of Central Australia 433–434 (1981); J.C.Tothill and
J.B.Hacker, Grasses Southern Qld 122–123 (1983); B.K.Simon, Key to
Australian Grasses
75 (1993); J.P.Jessop, Flora of South Australia
4: 1910–1911 (1986); S.W.L.Jacobs and S.M.Hastings, Flora of New South Wales
4: 587–589 (1993); N.G.Walsh, Flora of Victoria 2: 449–451 (1994);
D.I.Morris, Student's Flora of Tasmania 4B: 236–238 (1994);
E.Edgar and H.E.Connor, Flora of New Zealand 5: 301–306 (2000); D.Sharp
and B.K.Simon, AusGrass (2002); J.P.Jessop, Grasses of South
205–209 (2006); S.W.L.Jacobs, R.D.B.Whalley & D.J.B.Wheeler, Grasses
of New South Wales
, 4th Ed, 161–164 (2008);A.Wilson (ed.), Flora of
44A: Poaceae 2: 122–126 (2009).

W.D.Clayton &
S.A.Renvoize, Genera Graminum (1986), genus (173).

Naturalised. 27
species, from Europe, the Mediterranean, North Africa and western Asia. 6
species in Australia, WA, NT, SA, Qld, NSW, Vic, and Tas. Also Malesia and New

Habit. Annual,
tufted to decumbent. Leaf blades narrow or broad.

Inflorescence paniculate, an open panicle with branches ending in single
spikelets, open.

Spikelets laterally compressed, more than 2 flowered to 2 flowered, with 2 or
more fertile florets, awned, solitary, pedicelled; with naked rachilla
extension. Fertile spikelets disarticulating above glumes or not
disarticulating (cultivated forms).

Glumes. Glumes
more or less equal, about equal to spikelet or exceeding florets (rarely
shorter), long relative to adjacent lemmas, pointed, awnless, non-keeled,
similar (usually chaffy). Lower glume 3–11 nerved. Upper glume 3–11 nerved.

Fertile florets (1–)2–6. Lemmas similar in texture to glumes (rarely) or
decidedly firmer than glumes (usually leathery to crustaceous), becoming
indurated to not becoming indurated, incised, muticous or awned, without a germination
flap, 5–9 nerved, hairy or glabrous. Awns when present 1, dorsal, geniculate,
much longer than body of lemma. Palea relatively long or conspicuous and
relatively short or very reduced (but large), entire to apically notched,
tough, 2 nerved. Distal incomplete florets 1–2, underdeveloped. Callus pointed
(lanceolate). Lodicules 2. Ovary hairy. Stamens 3. Grain medium sized,
longitudinally grooved, compressed dorsiventrally, hairy on body. Hilum
long-linear. Embryo small.

Kranz Anatomy.

2n = 14,
28, 42, 48, and 63, 2, 4, 6, 7, and 9 ploid, commonly adventive.

Mesophytic, xerophytic. Mostly in weedy places. Species of open habitats.

Pooideae; Poeae.

Notes. A
uniform genus, varying mainly in lemma tip and mode of spikelet disarticulation
(Clayton & Renvoize, 1986).

Types Species. A.

. Clifford & Simon 1981, Simon & Jacobs 1990: Naturalised.

AVH 2011

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith