Aira caryophyllea L. subsp. caryophyllea

Sp. Pl. 1: 66 (1753).

T: Habitat in Angliae, Germaniae. Galliae glareosis

Illustrated in: Jessop & Toelken, eds. Fl. S. Australia 4: 1906 (1986).

Vegetative form. Annual, slender, erect, culms solitary or caespitose. Leaves mostly basal. Culms 5-35 cm high, branched above or unbranched above, 2-4 noded. Mid-culm nodes glabrous, exposed, pigmented or not pigmented, constricted. Mid-culm internodes hollow, scabrous (immediately below the node), terete. Young shoots intravaginal. Leaves non-auriculate. Basal leaf sheaths not keeled, terete, minutely retrorsely scabrous, the same colour as the lamina or purple, with the veins equally striate, with margins free, membranous, smooth. Ligule 3-5 mm long, not lobed, decurrent, membranous, smooth, acute, entire or laciniate (shortly), abaxially hairy (minutely scabrid). Collar scabrous. Distinct callus at blade-sheath junction absent. Leaf blades joining the sheath gradually, folded, linear, 20-55 mm long, 0.3-0.6 mm wide; adaxially puberulous, shallowly grooved; abaxially scabrous (hairs retrorse on the veins), with the veins equally striate; with margins scabrous, apices abruptly pointed or apices blunt and rounded, hooded. Prophyll 10 mm long, the keels scabrous.

Reproductive organization. Plants bisexual. Rudimentary spikelets at the base of the inflorescence, or absent. Incomplete spikelets absent.

Inflorescence. Inflorescence a panicle, silvery, erect, open, symmetrical, fully exserted. Main inflorescence axis 35-240 mm long. Peduncles 20-180 mm long, glabrous or scabrous, slightly ridged. Rachides 15-85 mm long, subterete, glabrous. Rachis angles glabrous. Pulvini present. Primary inflorescence branches minutely scabrous; paired, not branched at the base, spreading, filiform, distichous, without spikelets inserted at the base. Spikelets 1-2 on a typical ultimate inflorescence branch, on second order branches or on third order branches, erect, spreading.

Hermaphrodite (`perfect') spikelets. Hermaphrodite spikelets pedicellate, 2.3-3.1 mm long, laterally compressed, oblong, not disarticulating as a separate unit, disarticulating above the glumes. Pedicels 1.5-6 mm long (3/4-2 times the spikelet length), erect, slender (gradually thickened at apex), scabrous, straight. Glumes two per spikelet, similar, subequal, exceeding the florets (lower lemma c. 3/4s the glume length), usually longer than the proximal lemma. Lower glume narrowly ovate, 1.9-2.8 mm long, 0.4-0.7 mm wide, hyaline to membranous, weakly keeled (upper half), acute, entire, muticous, margin scabrous (i.e. serrate); 1 veined, midvein scaberulous; intercostal regions scaberulous (near the apex). Upper glume narrowly ovate, 2-2.5 mm long, 0.4-0.6 mm wide, hyaline to membranous, weakly keeled (upper half), acute, entire, muticous, margin scabrous; 3 veined (laterals short), veins obscure, midvein scaberulous; intercostal regions scaberulous (near apex). Rudimentary florets absent. Incomplete florets absent. Hermaphrodite florets 2 per spikelet (similar). Rachilla disarticulating between the florets, disarticulating directly below the florets, straight, segments 0.08-0.15 mm long, glabrous, shortly elongated between the upper glume and first floret and elongated between all florets, not apically prolonged. Callus present, blunt, 0.05 mm long, silky (straight, white, stiff, silky hairs), hairs to 0.3 mm long. Lemma similar in firmness to the glumes, laterally compressed, narrowly ovate, 1.8-2.3 mm long, 0.3-0.4 mm wide, membranous, not keeled, acuminate to acute, shortly bifid; awned. Lemma margins ciliolate (sparsely). Lemma 5 veined. Lemma veins not confluent apically, obscure, scaberulous, with the hairs on all the veins, with the hairs only at the vein apex; intercostal regions scaberulous, the hairs only at the apex. Awns 1, median. Median awn much longer than the body of the lemmas (and exserted from the glumes), 2.7-3.5 mm long, 1 veined, terete, dorsal, arising from the lower half of the lemma (1/3 the lemma length from the base), geniculate, column twisted (and pigmented), scabrous. Palea fully developed, 2/3s the length of the lemma to slightly shorter than the lemmas, similar in texture to the lemmas, gaping, narrowly elliptic, 1.3-1.6 mm long, 0.3 mm wide, membranous, 2-keeled, keels wingless, obtuse, bidentate, margin smooth; 2 veined, veins scaberulous (near apex); intercostal regions glabrous (lateral surfaces broad and overlapping). Lodicules 2, free, hyaline, oblong, acute to obtuse, smooth, with entire margins, glabrous. Stamens 3. Anthers 0.3-0.4 mm long, yellow, basally 2-lobed. Ovary obovoid, glabrous. Styles 2, apical, free to their bases.

Fruit. Fruit adhering to lemma, elliptical, laterally compressed and ventrally compressed, 1.1-1.25 mm long, 0.3 mm wide, not grooved, glabrous, without a fleshy apex. Hilum 0.1 mm long, punctiform, above the base. Embryo 0.15 mm long, not waisted, with an epiblast; endosperm hard.

Cytology. 2n = 28 (European, Chile).

Common name. Silvery Hairgrass.

Distribution. Introduced. Tasmania, New South Wales, Australian Capital Territory, Victoria, Western Australia, Queensland, and South Australia (N.T. ??). World distribution: Western Eurasia, USSR and Mediterranean.

Ecology. Mesophytic; in open habitats. Widespread in pastures and disturbed grassland. Flowers Nov.-??. Fruits March-??.

Vouchers. Specimens examined morphologically: A.C.T.: C.S.I.R.O. grounds, lower E slope of Black Mtn, Canberra, fine low grass non tufted, grassland, 11 Nov. 1963, R.Pullen 3924 (CANB); O'Connor, disturbed ground, 28 Nov. 1960, H.S.McKee 7663 (CANB). Vic.: Point Lonsdale, Oct.-Nov. 1912, J.E.Tilden 622 (CANB). Tas.: Bridport, NE Tasmania, 19 Nov. 1952, W.M.Curtis (CANB!, HO).

Notes. Economic importance: none.

Classification. Pooideae; Poodae; Aveneae.

References. Morphology: Jessop & Toelken, eds. Fl. S. Australia 4: 1906 (1986); Jacobs & Hastings, Fl. New South Wales ms. 172 (1992). Cytology: Tutin ed. (1980); Bowden & Senn (1962).

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