Common name
Giant Rat's Tail 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.

natalensis- from Natal, South Africa.

Published in
Consp. Fl. Afr. 5: 822 (1894).

Habit
Perennial, tufted. Basal leaf sheaths papery. Culms erect, 60–150 cm tall. Lateral branches simple. Ligule a fringe of hairs, 0.4 mm long. Leaf-blades linear, flat or conduplicate or convolute, 25–50 cm long, 2–4 mm wide. Leaf-blade apex filiform.

Inflorescence
Inflorescence compound, a panicle. Panicle open, pyramidal, 20–30 cm long, contracted about primary branches. Primary panicle branches ascending or spreading, 3–7 cm long, bearing spikelets almost to the base. Panicle branches glabrous in axils.

Spikelets
Spikelets solitary. Pedicels 0.7–1.5 mm long. Fertile spikelets 1-flowered, comprising 1 fertile floret, without rhachilla extension, lanceolate, terete, 1.6–2.3 mm long, breaking up at maturity. Spikelets disarticulating below each fertile floret.

Glumes
Glumes deciduous, dissimilar. Lower glume oblong, 0.5–0.8 mm long, 60% length of upper glume, hyaline, 0–1-nerved. Lower glume lateral nerves absent. Lower glume apex obtuse. Upper glume lanceolate or ovate, 0.8–1.3 mm long, 50% of length of adjacent fertile lemma, membranous, 1-nerved. Upper glume lateral nerves absent. Upper glume apex acute.

Florets
Fertile lemma ovate, 1.6–2.3 mm long, membranous, 1-nerved. Lemma apex acute. Palea 2-nerved. Palea keels approximate. Palea apex entire, obtuse. Anthers 3, 0.8–1 mm long. Grain with free soft pericarp, ellipsoid or obovoid, quadrangular, 0.7–0.8 mm long.

Continental Distribution:
Africa, Temperate Asia, Australasia.

Australian Distribution:
Northern Territory, Queensland, New South Wales.

Northern Territory: Darwin & Gulf. Queensland: North Kennedy, Darling Downs, Moreton, Port Curtis, Wide Bay. New South Wales: North Coast, Southern Tablelands, North-Western Slopes.

Classification. (GPWG 2001):
Chloridoideae: Cynodonteae

Notes
Introduced; mainly from Rockhampton, Qld to Port Macquarie, N.S.W.; a few other records elsewhere; Southern and central Africa and the Pacific region. Flowers Jan.–July, Oct.–Dec.
Together with Sporobolus pyramidalis comprises the pasture grass weed Giant Ratstail Grass. Differs from S. pyramidalis by the upper glume being at least half the spikelet length and pointed.