Arrhenatherum elatius (L.) P.Beauv. ex J.Presl & C.Presl, Spenn. in Fl. Friburg. 1: 113 (1825).

Avena elatior L., Sp. Pl. 1: 79 (1753). T: Habitat in Europae maritimus & apricis.
Arrhenatherum avenaceum (Scop.) P.Beauv., Ess. Agrostogr. 55, 152, 153, t. 11, fig. 5 (1812)

Illustrated in: Hubbard (1976) p. 10, 208.

Vegetative form. Perennial, erect or ascending, caespitose. Basal culm internodes swollen, or not swollen. Leaves scattered along the culms. Culms 57-180 cm high, unbranched above, 3-9 noded. Mid-culm nodes rarely sparsely hairy or glabrous (the upper often pubescent), exposed, pigmented or not pigmented, swollen or constricted. Mid-culm internodes hollow, glabrous or puberulous (sparsely, immediately below the node), terete. Leaves non-auriculate. Basal leaf sheaths upwardly keeled, terete, glabrous, the same colour as the lamina or purple (slightly, at the base), with midrib prominent (near top) or with the veins equally striate, with margins free, hyaline to membranous, smooth (decaying to fibres). Ligule 0.9-2(-3) mm long, not lobed, decurrent, membranous, obscurely ciliolate or smooth, acute or obtuse or truncate, entire or erose, abaxially minutely hairy. Collar glabrous, or pilose (the hairs sparse). Distinct callus at blade-sheath junction absent. Leaf blades joining the sheath gradually, flat, linear, 130-230(-400) mm long, 4-6(-10) mm wide; adaxially glabrous or adaxially scabrous and adaxially pilose or adaxially pilose (the hairs sparse), channelled or shallowly grooved or not grooved; abaxially glabrous or abaxially scabrous, with midrib prominent; with margins scabrous, apices acute, flat (but the margins inrolled at the apex); convolute in bud.

Reproductive organization. Plants bisexual. Rudimentary spikelets at the base of the inflorescence. Incomplete spikelets absent. Inflorescence of chasmogamous spikelets.

Inflorescence. Inflorescence a panicle, green to purple, shining, erect or nodding, contracted (i.e. narrow), to 35 mm wide, oblong or ovate, symmetrical, fully exserted. Main inflorescence axis 280-615 mm long. Peduncles 190-430 mm long, glabrous, finely ridged. Rachides 90-220 mm long, terete, glabrous or scabrous (sparsely). Pulvini absent. Primary inflorescence branches scabrous; clustered (to 8-nate), branching at the base or not branched at the base, narrowly spreading, clusters distichous, without spikelets inserted at the base. Spikelets 1-3 on a typical ultimate inflorescence branch, on first order branches or on second order branches or on third order branches, erect, spreading, subtending foliar structure often present.

Hermaphrodite (`perfect') spikelets. Hermaphrodite spikelets pedicellate, 7.7-10.2 mm long, (3.8-)8.5-9 mm wide, laterally compressed, cuneate, not disarticulating as a separate unit, disarticulating above the glumes. Pedicels 1.7-8.5 mm long, erect, slender, scabrous, straight to sinuous. Glumes two per spikelet, dissimilar, unequal in length, about equalling the florets, approximately half the proximal lemma in length or slightly shorter than the proximal lemma or equalling the proximal lemma or longer than the proximal lemma. Lower glume c. 1/2 the length of the upper glume or c. 2/3s the length of the upper glume, narrowly ovate, 4.3-6.4 mm long, 0.6-1.1 mm wide, hyaline, keeled, acuminate to acute, entire, muticous, margin smooth or margin ciliolate (obscurely and sparsely at the apex); 1 veined, midvein scaberulous; sparsely intercostal regions scaberulous. Upper glume narrowly ovate, 7.2-10.6 mm long, 1.2-2.1 mm wide, hyaline, keeled, acute, entire, muticous, margin smooth or margin ciliolate (obscurely, near the apex); 3(-5) veined, veins prominent, midvein scaberulous; intercostal regions scaberulous. Rudimentary florets distal to the hermaphrodite florets, or absent. Incomplete florets present or absent, proximal to the hermaphrodite florets. Proximal incomplete florets usually 1 per spikelet, male, similar in morphology to hermaphrodite florets, awned, paleate. Incomplete lemmas decidedly firmer than the glumes, more or less equal to the hermaphrodite lemma, narrowly ovate to narrowly elliptic, 7.7-9 mm long, 1.3-1.5 mm wide, membranous to chartaceous, keeled or not keeled, apices acuminate to acute, entire, stoutly awned, with margins smooth or with margins scabrous; 7 veined. Incomplete lemma veins not confluent apically, distinctly raised; scabrous, with hairs on all veins, extending the length of the veins or only at the vein apex; intercostal regions scabrous or pilose, the hairs over most of the dorsal surface or only at the base. Incomplete lemma awns 1, median. Incomplete lemma median awn dorsal, much longer than the body of the lemmas (arising below the middle (from 1/4-2/3s the length from the base) geniculate, column strongly twisted), 11.9-16 mm long. Proximal male florets with 1-3 stamens (?). Hermaphrodite florets 1(-3) per spikelet. Rachilla not disarticulating between the florets, straight, segments 0.4 mm long, glabrous or pubescent (the hairs sparse), elongated between all florets, apically prolonged; prolongation 0.4-2 mm long, terminated by a rudimentary floret (a very reduced structure). Callus present, blunt, 0.2-0.4 mm long, silky (hairs straight, white), hairs 0.9-2.6 mm long. Lemma decidedly firmer than the glumes, slightly laterally compressed, narrowly ovate to narrowly elliptic, 8-10 mm long, 1.1-1.9 mm wide, membranous to chartaceous, upwardly keeled, acute, entire or bidentate (shortly); apex hyaline; muticous or awned (a rudimentary subapical awn, or rarely a distinct awn). Lemma margins smooth or scabrous (minutely). Lemma 7 veined. Lemma veins not confluent apically, prominent, the laterals raised and the marginals raised, scaberulous, with the hairs on all the veins, with the hairs extending the length of the veins; intercostal regions glabrous or scaberulous or scaberulous and silky (antrorse, straight, stiff hairs as on callus, to 1 mm long), the hairs over the entire dorsal surface or only at the base. Awns 1, median (awn either weak, short and straight or as on male floret). Median awn shorter than the body of the lemmas or about as long as the body of the lemmas, 0.9-12 mm long, 1 veined, terete, dorsal, arising from the mid-point of the lemma, straight or geniculate, strongly column twisted or column not twisted, scabrous. Palea fully developed, slightly shorter than the lemmas or equalling the lemmas, thinner than the lemmas, tightly clasped by the lemmas, narrowly elliptic or oblanceolate, 6.4-8.5 mm long, 0.6-0.9 mm wide, hyaline, 2-keeled, keels wingless, acute to truncate, entire or bidentate, margin smooth; 2 veined, veins scaberulous to veins puberulous (scabrous on the upper 3/4s); intercostal regions glabrous, or intercostal regions scabrous (hairs sparse). Lodicules present, 2 (prominent), free, hyaline, subulate to ovate, acute, smooth, toothed or with entire margins, with margin divisions lateral (small, near base), glabrous. Stamens 3. Anthers 4.3-5.1 mm long, yellow, basally 2-lobed (c. 1/4). Ovary obovoid, pubescent (hairs antrorse, dense), with the hairs over the entire ovary. Styles 2, apical, free to their bases.

Fruit. Fruit free from both lemma and palea, elliptical or oblong (c. terete in T.S.), laterally compressed, 4.5-5.1 mm long, 1.1-1.3 mm wide, not grooved, pubescent, with dense hairs, the hairs covering most of the body, without a fleshy apex. Hilum 2.5-3.5 mm long (1/2-2/3s the fruit length), linear. Embryo 1.3-1.7 mm long (c. 1/3 the fruit length), not waisted, with an epiblast; endosperm hard.

Cytology. 2n = 28 (European).

Distribution. Introduced. Tasmania, New South Wales, Australian Capital Territory, Victoria, Queensland, and South Australia. World distribution: Western Eurasia, USSR, Eastern Asia, Mediterranean, Africa, and North America.

Ecology. Mesophytic. A weed of dry grasslands. Flowers Nov.-Jan. Fruits Nov.

Notes. Economic importance: used for making hay and for grazing.

Classification. Pooideae; Poodae; Aveneae.

References. Morphology: Tutin (1980) p. 216; Clayton & Renvoize (1986) p. 124; Hubbard (1976) p. 209; Wheeler et al. (1990) p. 118; Jacobs & Hastings (1992) ms p. 167-168; Morris, D.I. (1991). Grasses Tasman. 60. Cytology: Tutin (1980) p. 216.

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