Sporobolus africanus (Poir.) Robyns & Tournay

synonyms: Sporobolus capensis


African ratstail, African dropseed, rat-tail, smutgrass, parramatta Grass


Info

Subfamily: Chloridoideae
Genus etymology: Sporobolus = "seed thrower" referring to the seed being ejected from the pericarp
Species etymology: africanus = from Africa
Photosynthetic type: C4 (warm season)
Nativity: naturalized - accidental
First recorded in Hawaiʻi: 1903

Map

 Distribution of Sporobolus africanus in Hawaiʻi.
 Distribution of Sporobolus africanus in Hawaiʻi.

Inflorescence

Sporobolus africanus Inflorescence
Sporobolus africanus Inflorescence
Sporobolus africanus Inflorescence
Sporobolus africanus Inflorescence
Sporobolus africanus Inflorescence

Plant

Sporobolus africanus Plant

Habit

Sporobolus africanus Habit

Spikelets

Sporobolus africanus Spikelets
Sporobolus africanus Spikelets
Sporobolus africanus Spikelets
Sporobolus africanus Spikelets
Sporobolus africanus Spikelets
Sporobolus africanus Spikelets
Sporobolus africanus Spikelets
Sporobolus africanus Spikelets
Sporobolus africanus Spikelets
Sporobolus africanus Spikelets

Description

Tufted perennial, the basal sheaths rather broad and somewhat papery; culms 30–110 cm. high, 1.5–3 mm. in diameter at the base. Leaf-blades flat or convolute, up to 40 cm. long, 1–4 mm. wide, tapering to a long filiform tip. Panicle linear with short side branches to spiciform, 10–35 cm. long, dense; primary branches appressed to the main axis, subsecund, densely spiculate along their whole length, the lowest 1–2 cm. long. Spikelets (1.5–)2.1–2.8 mm. long, dark green; lower glume broadly oblong, 0.4–0.7 mm. long, hyaline, obtuse; upper glume narrowly ovate, 1–1.5 mm. long, ± 1/2 as long as the spikelet, acute; lemma ovate-elliptic, as long as the spikelet, acute; anthers 3, 0.6–0.8 mm. long. Grain ellipsoid, (0.8–)1.1– 1.2 mm. long, truncate at the top, often ± tetragonal in cross-section.
(Description source: Clayton, W.D. 1970. Flora of Tropical East Africa. Gramineae (Part 1). Crown Agents for Oversea Governments and Administrations, London. 176 pp. )

Caespitose perennial without rhizomes or stolons; culms up to 130 cm tall, erect, unbranched; basal leaf sheaths broad, chartaceous, glabrous, laterally compressed, persistent; leaf laminas up to 40 cm × 1–4 mm, flat or involute, glabrous or scaberulous on the surfaces, thinly scabrid on the margins, tapering to a long filiform apex.Panicle (10)20–45 cm long, linear to spiciform; primary branches not in whorls, appressed to the main axis 1–2 cm long, thinly scabrid, eglandular, subsecund, the spikelets densely arranged along their whole length.Spikelets 1.7–2.6 mm long, greyish-green to dark green; inferior glume 1/5–2/5 the length of the spikelet, broadly oblong, hyaline, nerveless, glabrous, obtuse at the apex; superior glume 2/5–3/5 the length of the spikelet, narrowly ovate, hyaline, 1-nerved, glabrous, acute at the apex; lemma as long as the spikelet, ovate-elliptic, acute; anthers 3, 0.6–1.2 mm long.Grain (0.8)1–1.2 mm long, elliptic to obovate, truncate at the top, tetragonal in section.
(Description source: Pope, G.V. (ed). 1999. Flora Zambesiaca. Volume 10. Part 2. Kew, London. 261 pp. )

Habit: Perennial; caespitose. Butt sheaths papery. Culms erect; 30-110 cm long; 1.5-3 mm diam. Ligule a fringe of hairs. Leaf-blades flat, or convolute; 20-40 cm long; 1-4 mm wide. Leaf-blade apex filiform. Inflorescences: Inflorescence a panicle. Panicle contracted, or spiciform; linear; 10-35 cm long; contracted about primary branches. Primary panicle branches appressed; 1-2 cm long; bearing spikelets almost to the base. Panicle branches glabrous in axils. Spikelets solitary. Fertile spikelets pedicelled. Spikelets: Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; (1.5-)2.1-2.8 mm long; breaking up at maturity; disarticulating below each fertile floret. Fertile Spikelets: Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; subterete; (1.5-)2.1-2.8 mm long; breaking up at maturity; disarticulating below each fertile floret. Glumes: Glumes deciduous; dissimilar; shorter than spikelet. Lower glume oblong; 0.4-0.7 mm long; 0.4-0.5 length of upper glume; hyaline; without keels; 1 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume ovate; 1-1.5 mm long; 0.5 length of adjacent fertile lemma; membranous; dark green; without keels; 1 -veined. Upper glume lateral veins absent. Upper glume apex acute. Florets: Fertile lemma ovate; (1.5-)2.1-2.8 mm long; membranous; dark green; without keel; 1 -veined. Lemma apex acute. Palea 2 -veined. Palea keels approximate. Flowers: Anthers 3; 0.6-0.8 mm long. Fruits: Caryopsis with free soft pericarp; ellipsoid; quadrangular; (0.8-)1.1-1.2 mm long. Distribution: Africa: Macaronesia, west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, south, middle Atlantic ocean, and western Indian ocean. Asia-temperate: Arabia. Asia-tropical: India, Malesia, and Papuasia. Australasia: Australia and New Zealand. Pacific: southwestern, south-central, northwestern, and north-central.
(Description source: Clayton, W.D., Vorontsova, M.S., Harman, K.T. and Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora. Available at https://powo.science.kew.org )

Perennials; culms sparsely to densely tufted, wiry, 3-10 dm tall. Sheaths 4-12 cm long, compressed, pilose at throat and - along margins but otherwise glabrous; ligule ciliate, less than 0.2 mm long; blades flat to weakly involute, 10-25 cm long, 2-5 mm wide at base, glabrous, apex attenuate. Panicles 15-25 cm long, erect, spike-like, sometimes interrupted at base, branches short, closely appressed; spikelets (1.5-)2- 2.8 mm long, glabrous; first glume oblong, 0.4-0.7 mm long, apex obtuse, second glume ovate, 1-1.5 mm long, apex acute; lemma oblong to lanceolate, ca. 2 mm long, faintly 3-nerved, hyaline, apex obtuse to acute; palea as long as lemma. Fruit dark red, obovate, 1.2-1.5 mm long, apex obtuse to truncate, readily separating from the spikelet but often adhering to the panicle for some time after maturity by the mucilaginous pericarp. [2n = 18, 36.]
(Description source: O’Connor, P.J. 1990. Poaceae, pp. 1481–1604. In: Wagner W.L., Herbst D.R. & Sohmer S.H. (eds.)., Manual of the flowering plant of Hawaiʻi. Vol. 2. University of Hawaii Press & Bishop Museum Press, Honolulu )