Agrostis gigantea Roth, Tent. Gl. Germ. 1: 31 (1788).

A. alba auct., non L.

Vegetative form. Perennial, rhizomatous and caespitose (the rhizomes with 3 or more scale leaves). Culms to 150 cm high, 4-6 noded. Mid-culm nodes glabrous. Mid-culm internodes glabrous, terete. Leaves non-auriculate. Basal leaf sheaths not keeled, terete, glabrous or scabrous, with the veins equally striate. Ligule 1.5-6 mm long, membranous, obtuse or truncate, erose or laciniate. Leaf blades flat, to 200 mm long, 1-6(-8) mm wide; adaxially scabrous, shallowly grooved; abaxially scabrous; with margins scabrous, apices acuminose (tapering to a fine point); convolute in bud.

Reproductive organization. Plants bisexual. Incomplete spikelets absent. Inflorescence of chasmogamous spikelets.

Inflorescence. Inflorescence a panicle, green or green and purple, erect, open, symmetrical (oblong to ovate, loose during flowering). Rachides to 300 mm long, glabrous and scabrous. Primary inflorescence branches scabrous, spreading (naked at the base).

Hermaphrodite (`perfect') spikelets. Hermaphrodite spikelets pedicellate, 2-3 mm long, laterally compressed, not disarticulating as a separate unit, disarticulating above the glumes. Pedicels slender, clavate tips often scabrous. Glumes two per spikelet, similar, subequal, exceeding the florets, longer than the proximal lemma. Lower glume longer than the upper glume, ovate, membranous, keeled, acuminate to acute, muticous; 1 veined, midvein scabrous. Upper glume ovate, membranous, keeled (only at the apex), acuminate to acute, muticous; 1 veined, midvein scabrous. Rudimentary florets absent. Incomplete florets absent. Hermaphrodite florets 1 per spikelet. Callus present, blunt. Lemma less firm than the glumes, laterally compressed, ovate, 1.5-2 mm long, membranous, not keeled, truncate, shortly dentate; usually muticous and aristate or awned and aristate. Lemma 3(-5) veined. Lemma veins not confluent apically (extending beyond the axis as minute bristles), glabrous; intercostal regions glabrous. Awns 1, median. Median awn shorter than the body of the lemmas, 1 veined, dorsal; arising from the upper half of the lemma. Palea fully developed, 1/2 the length of the lemmas to 2/3s the length of the lemma, hyaline, shortly bifid. Lodicules 2, hyaline, ovate. Stamens 3. Anthers 1-1.5 mm long. Ovary glabrous. Styles 2, free to their bases.

Fruit. Fruit not seen.

Common name. Redtop Bent.

Distribution. Introduced. Tasmania, New South Wales, Australian Capital Territory, Victoria, Western Australia, Queensland, and South Australia.

Ecology. Mesophytic. Grows near water, a weed of pasture and roadsides. Flowers spring-summer.

Classification. Pooideae; Poodae; Aveneae.

References. Morphology: Morris 83 (1991); Jacobs & Hastings (1994).

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