Common name
Rat's Tail Grass
Wire Grass

Derivation
Sporobolus R.Br., Prodr. 169 (1810); from the Greek spora (seed) and bolos (throwing), alluding to the free seed and (presumably) the sometimes forcible manner of its release.

jacquemontii- in honour of Victor Jacquemont (1801–1832), French naturalist and traveller.

Published in
Rev. Gram. 427, t.127 (1831).

Common synonyms
Sporobolus pyramidalis P.Beauv. var. jacquemontii (Kunth) Jovet & Guédès

Habit
Perennial, densely tufted. Basal leaf sheaths herbaceous. Culms erect, 50–75 cm tall, 1–5 mm diam. Lateral branches simple. Ligule a fringe of hairs, 0.2–0.3 mm long. Leaf-blades filiform, flat or conduplicate or convolute, to 40 cm long, 2.5–3.5 mm wide. Leaf-blade apex attenuate, callose.

Inflorescence
Inflorescence compound, a panicle. Panicle open, lanceolate, 8–25 cm long, 0.5–3 cm wide, contracted about primary branches to evenly furnished. Primary panicle branches spreading, 5–10 cm long, bearing spikelets almost to the base. Panicle branches glabrous in axils.

Spikelets
Spikelets solitary. Pedicels linear, 0.5–1 mm long. Fertile spikelets 1-flowered, comprising 1 fertile floret, without rhachilla extension, lanceolate, terete, 1.5–2 mm long, breaking up at maturity. Spikelets disarticulating below each fertile floret.

Glumes
Glumes deciduous, similar, subequal in width, thinner than fertile lemma. Lower glume lanceolate or elliptic or oblong, 0.3–0.4 mm long, 50–80% length of upper glume, 0-nerved. Lower glume apex obtuse. Upper glume lanceolate or oblong, 0.5–0.8 mm long, 30–40% of length of adjacent fertile lemma, hyaline, 1-nerved. Upper glume lateral nerves absent. Upper glume apex obtuse.

Florets
Fertile lemma elliptic or ovate, 1.7–2 mm long, membranous, 1-nerved. Lemma apex acute. Palea 2-nerved. Palea keels approximate. Palea apex entire, obtuse. Anthers 3, 0.6–1.1 mm long. Grain with free soft pericarp, oblong or obovoid, quadrangular, 0.8–1 mm long.

Continental Distribution:
Africa, Australasia, North America, South America.

Australian Distribution:
Northern Territory, Queensland.

Northern Territory: Darwin & Gulf. Queensland: Cook, North Kennedy, South Kennedy, Port Curtis, Leichhardt, Wide Bay, Moreton.

Classification. (GPWG 2001):
Chloridoideae: Cynodonteae

Notes
Introduced. Mainly from Cape York to SE Qld; also in Africa, the Pacific region, North America, S America, Central America, and West Indies. Of tropical American origin it has been established in Australia for a long time and has even been suggested as being native (Simon 1982, Jacobs & McClay 1992) due to its being collected in relatively undisturbed areas. Flowers all year.