Avena barbata Pott ex Link, In Schrader, Jour. für die Bot. 1799 (2): 315 (1800).

A. strigosa subsp. barbata (Pott ex Link) Thell., .
A. alba auct. non Vahl.,

Vegetative form. Annual, erect or geniculate (rarely prostrate), caespitose. Leaves mostly basal. Culms 45-140 cm high, unbranched above, 2-4 noded. Mid-culm nodes glabrous, exposed, pigmented, constricted. Mid-culm internodes hollow, glabrous (often slightly glaucous), terete. Young shoots intravaginal. Leaves non-auriculate. Basal leaf sheaths not keeled, terete, usually glabrous or pubescent to pilose, the same colour as the lamina or purple, with the veins equally striate, with margins free, membranous, smooth. Ligule (2-)4-7.7 mm long, not lobed, decurrent, membranous to chartaceous, obscurely and sparsely ciliolate, obtuse, erose, abaxially hairy (minutely scabrid). Collar glabrous. Distinct callus at blade-sheath junction absent. Leaf blades joining the sheath gradually, flat, linear, 80-275 mm long, 3-6(-8) mm wide; adaxially scabrous, shallowly grooved; abaxially scabrous, with midrib prominent; with margins scabrous or with margins scabrous and with margins ciliate, apices acute (tapering to point); convolute in bud. Prophyll 20-25 mm long, glabrous.

Reproductive organization. Plants bisexual. Rudimentary spikelets at the base of the inflorescence, or absent. Incomplete spikelets absent. Inflorescence of cleistogamous spikelets and chasmogamous spikelets (?).

Inflorescence. Inflorescence a panicle, pallid to green to purple, nodding, open, one-sided, fully exserted. Main inflorescence axis 300-945 mm long. Peduncles 130-695 mm long, glabrous, slightly ridged. Rachides 75-365 mm long, terete, glabrous. Pulvini present. Primary inflorescence branches glabrous or scabrous (lightly); clustered, branching at the base or not branched at the base, spreading or divaricate or reflexed, distichous. Spikelets 1-2 on a typical ultimate inflorescence branch, on first order branches or on second order branches or on third order branches, pendulous.

Hermaphrodite (`perfect') spikelets. Hermaphrodite spikelets pedicellate, 18-30 mm long, 13-20 mm wide, laterally compressed, cuneate, not disarticulating as a separate unit, disarticulating above the glumes. Pedicels 4-65 mm long, erect or recurved, slender (distally dilated), antrorsely scabrous. Glumes two per spikelet, similar (occasionally purplish near base), equal in length or subequal, about equalling the florets or exceeding the florets, equalling the proximal lemma or longer than the proximal lemma. Lower glume narrowly oblong to narrowly ovate, 20-26(-30) mm long, 2-3 mm wide, membranous, dorsally rounded, subulate, entire, muticous, margin smooth or margin ciliolate (obscurely); (5-)8-10 veined, veins prominent (transverse veins obscure), midvein scaberulous (sparsely near apex); intercostal regions glabrous. Upper glume narrowly oblong to narrowly ovate, 21-30 mm long, 2-3 mm wide, membranous, dorsally rounded, subulate, entire, muticous, margin smooth or margin scabrous (obscurely); (7-)9-10 veined, veins prominent (transverse veins obscure), midvein scaberulous (near apex); intercostal regions glabrous. Rudimentary florets distal to the hermaphrodite florets. Incomplete florets absent. Hermaphrodite florets 2-3 per spikelet. Rachilla disarticulating between the florets, disarticulating directly below the florets, straight, segments 2.5-3.5 mm long, silky (hairs to 4.3 mm long), elongated between all florets, apically prolonged; prolongation silky, 3-5.5 mm long, terminated by a rudimentary floret. Callus present, blunt, 1.3 mm long, densely silky, hairs to 4.3 mm long. Lemma decidedly firmer than the glumes, laterally compressed, narrowly oblong to narrowly ovate, (15-)20-26 mm long, 2-3 mm wide, coriaceous, not keeled, subulate, bifid, 2-4 -lobed; apex membranous; awned and aristate. Lemma margins membranous; smooth or ciliolate (obscurely, toward apex). Lemma 7 veined. Lemma veins not confluent apically, prominent (near the apex), the laterals raised and the marginals raised, connected by obscure transverse veins, scaberulous and silky, with the hairs on all the veins, with the hairs extending the length of the veins (scabrous near the apex, silky below the point of awn insertion); intercostal regions scaberulous and silky, the hairs over the entire dorsal surface (scabrous near apex, silky below awn insertion). Awns 1, median and lateral. Median awn much longer than the body of the lemmas (c. 2-21/2 times the lemma), 40-50(-60) mm long, 1 veined, different in form from the lateral awns, terete, dorsal; 13.5-19 mm below tip; arising from the lower half of the lemma, geniculate, column twisted (stout, usually dark brown), scabrous. Lateral awns shorter than the median awn, 2-4.5 mm long. Palea fully developed, 2/3s the length of the lemma, thinner than the lemmas, gaping, narrowly oblong or narrowly elliptic, 12-14.5 mm long, 1.7-3 mm wide, lateral faces hyaline and membranous (firmly, dorsally), 2-keeled, keels winged (narrowly), acute or obtuse, apically notched or bidentate (shortly), margin smooth; 2 veined, veins ciliate (hairs to 0.4 mm long, for most of the keel but longer and denser upper 2/3s); sparsely intercostal regions puberulous. Lodicules 2, free, hyaline, ovate or oblong, acute, smooth, with entire margins, glabrous. Stamens 3. Anthers yellow, entire or shortly basally 2-lobed. Cleistogamous anthers 3 mm long. Ovary obovoid, antrorsely silky, with the hairs over the entire ovary. Styles 2, apical, free to their bases.

Fruit. Fruit free from both lemma and palea, oblong, laterally compressed and ventrally compressed, 7.7 mm long, 1.5 mm wide, longitudinally grooved, silky, with dense hairs, the hairs covering most of the body, with a fleshy apex. Hilum 6.4 mm long (?), linear, at the base. Embryo 2.5-2.6 mm long, not waisted, with an epiblast; endosperm hard.

Common name. Bearded Oats.

Distribution. Introduced. Tasmania, New South Wales, Victoria, Western Australia, and South Australia. World distribution: Mediterranean.

Ecology. Mesophytic. Common weed of disturbed land. Flowers Sept.-Nov. Fruits Oct.-Dec.

Vouchers. Specimens examined morphologically: W.A.: Kings Park, Perth, sandy soil, 20 Sept. 1934, R.Roe (CANB); Boullanger Is., c. 1 km from mainland, Jurien Bay, clumped grass 60 cm high, flowers greenish brown, common in low shrubland, deep white sand over limestone, 31 Oct. 1985, G.J.Keighery & J.J.Alford 272 (CANB!, PERTH). Oraparinna National Park, above Aroona Valley on W facing slope of the ABC Range, 12 Sept. 1971, D.E.Symon 7238 (AD, CANB!). N.S.W.: Cowra, 23 km N on Midwestern Hwy, 18 Nov. 1992, N.Lloyd 1240 (CANB); Temora, common along roads in Young-Temora-Cootamundra-Harden area, to 1.5 m tall, 2 Nov. 1969, J.W.Vickery (CANB!, NSW); Yass, 34 km S on Wee Jasper Rd, 9 Nov. 1985, 9 Nov. 1985, N.Lloyd 295 (CANB); Sutton Forest, 7 Dec. 1987, N.Lloyd 669 (CANB); Willoughby, Sydney, suburban garden, 18 Edinburgh Rd, panicle one-sided, 25 Dec. 1962, M.Gray 5324 (CANB); Blayney, urban area, 15 Nov. 1992, N.Lloyd 1255 (CANB). Tas.: Huon Rd, 23 Dec. 1951, W.M.Curtis (CANB!, HO).

Classification. Pooideae; Poodae; Aveneae.

References. Morphology: S.W.L.Jacobs & S.M. Hastings, ; Morris 61 (1991).

Cite this publication as:
C.M. Weiller, M.J. Henwood, J. Lenz and L. Watson (1995 onwards). `Pooideae (Poaceae) in Australia - Descriptions and Illustrations'. URL http://muse.bio.cornell.edu/delta/
Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993) should also be cited.

References and Acknowledgements