Guinea Grass

Guinea Grass is a native of tropical Africa introduced into most other warm countries and well established in Pakistan. Its introduction to India probably dates from before 1800. It is an outstanding fodder grass readily eaten by cattle.

Morphologically it is extremely variable ranging from tall very robust plants about 3 m high to small plants less than 1 m high. The spikelets may be glabrous or pubescent. Tall specimens (especially those of southern India, Africa and North America) are distinguished from the North American Panicum plenum, by the bearded nodes and longer ligules, but this does not hold for Pakistani plants. These are nearly all the small variant and mostly have pubescent spikelets, the latter character being the best distinguishing feature since the nodes of these plants are usually glabrous.

Perennials; rhizome stout, culm erect, node densely hirsute. Blade 30-75 cm long, to 35 mm wide; sheath papillate-hirsute to glabrous; ligule 4-6 mm long. Panicle open, 20-35 cm long, axils pilose, lower branches whorled. Spikelets 3-3.5 mm lng, obtuse, usually glabrous, faintly veined, mostly purplish red or flushed with purple; glumes unequal; lower glume ca. 1/3 length of spikelet, 1-3-veined or veinless; upper glume 5-veined; lower lemma usually staminate, rarely empty, 5-7-veined; upper lemma distinctly transversely rugose, stramineous, coriaceous.

Perennial, rhizomatous; rhizome stout. Culms robust, erect, 1–3 m tall, nodes glabrous or pilose. Leaves basal and cauline; leaf sheaths glabrous to hispid; leaf blades linear to narrowly lanceolate, flat, 20–60 × 1–3.5 cm, narrowed at base, glabrous or pilose, margins scabrid, apex acuminate; ligule 1–3 mm, membranous, with dense cilia dorsally. Panicle oblong or pyramidal in outline, 10–45 cm, much branched; branches spreading, lowest arranged in a whorl. Spikelets oblong, 3–4.5 mm, glabrous or pubescent, often tinged purple, obtuse or acute, occasionally overtopped by long hairs from apex of pedicel; lower glume broadly ovate, 1/3–1/2 length of spikelet, 3-veined, obtuse or acute; upper glume ovate-oblong, as long as spikelet, 5-veined, acute; lower floret staminate, lemma similar to upper glume, palea well developed; upper floret thinly coriaceous, pale yellow or green, shiny, finely transverse rugulose. Fl. and fr. Aug–Oct. 2n = 32.

Densely tufted perennial; culms 80-300 cm high, erect or ascending, often branched, the nodes usually bearded. Leaf-blades linear, 10-60(80) cm long, 4-20 (-40) mm wide, flat, glabrous, long-tapering to a fine point; lowermost sheaths strongly compressed and keeled. Panicle ovate, 10-45 cm long, contracted or open, the branches mostly bare in the lower half, the lowermost conspicuously whorled. Spikelets oblong, 2.5-3.6(4) mm long, glabrous or shortly and densely pubescent, acute or subobtuse; lower glume orbicular, hyaline, a quarter to a third the length of the spikelet, rounded or shortly acute, 1-3-nerved or sometimes almost nerveless; upper glume 5-7-nerved; lower lemma 5-7-nerved, its palea almost as long; upper lemma pallid, rugulose.

Originally from tropical Africa, introduced elsewhere. Taiwan, in grassland, roadsides, riverbanks, plantations and disturbed places.

Distribution: Pakistan (Punjab & N.W.F.P.; introduced); tropical Africa; introduced to most other warm countries.

Fl. & Fr. Per.: June-October.

Widely cultivated for forage. Guangdong, Taiwan [native to tropical Africa and America].

Megathyrsus maximus (Jacquin) B. K. Simon & S. W. L. Jacobs; Panicum hirsutissimum Steudel; P. jumentorum Persoon; P. maximum var. hirsutissimum (Steudel) Oliver; P. poly-gamum Swartz.