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.

maximum: largest

Tall tufted perennial, usually 1-2 m tall, occasionally much taller. Inflorescence a large open panicle, pyramidal or oblong in outline with the lower branches often whorled. Spikelets 3-4.5 mm, glabrous or pubescent, sometimes overtopped by long hairs from tip of pedicel; lower glume broadly ovate, 1/3 to 1/2 length of spikelet, 3-nerved; upper glume ovate-oblong, 5-nerved, acute; lower lemma ovate-oblong, 5-nerved; upper lemma strongly transversely rugose.

Common

Panicum maximum Jacq. Coll. 1: 76. 1786
Panicum polygamum Sw. Prodr. 24. 1788.
Panicum laeve I^am. Tab. Kncyc. 1: 172. 1791.
Panicum jumentorum Pers. Syn. PI. 1: 83. 1805.
Panicum scaberrimum Lag. Gen. & Sp. Nov. 2. 1816.
Panicum trichocondylum Steud. Syn. Gram. 74. 1854.
Panicum praticola Salzm.; Doell, in Mart. Fl. Bras. 2 2 : 203, as synonym. 1877.
Plants light-green, 1-2.5 meters high, or taller in cultivation, in tufts of few to many culms, from creeping rootstocks ; culms robust, erect or sometimes geniculate and rooting at the lower nodes, glabrous, the nodes usually densely hirsute; leaf-sheaths shorter than the internodes, papillose-hirsute to glabrous-ciliate, usually a dense ring of pubescence at the juncture with 225
the blade; ligule 4-6 mm. long, stiffly and densely ciliate from a membranaceous base; blades erect or ascending, flat, 30-75 cm. long, 1-3.5 cm. wide, very scabrous on the margin, otherwise glabrous, or hirsute on the upper surface at the base; panicles finally long-exserted, 20-50 cm. long, usually about one third as wide, densely flowered, the long, rather stiff branches ascending, naked at the base, the lower in whorls, the axils pilose, the branchlets short, appressed, bearing more or less clustered, short-pediceled spikelets; spikelets 3-3.3 mm. long, 1-1.1 mm. wide, and about as thick, oblongellipsoid, glabrous, somewhat shining, faintly nerved; first glume about one third the length of the spikelet, obtuse; second glume and sterile lemma subequal, slightly exceeding the fruit, thin in texture, the lemma inclosing a staminate flower; fruit 2.3-2.5 mm. long, about 1 mm. wide, elliptic, transversely rugose, minutely puberulent at the apex.
Type locality: Guadeloupe.
Distribution: Introduced in America, from Florida, Mexico, and the West Indies to tropical South America; also in the tropical parts of the Old World.

Perennials, Terrestrial, not aquatic, Rhizomes present, Rhizome short and compact, stems close, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate , decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem nodes bearded or hairy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems with inflorescence 2-6 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath hairy, hispid or prickly, Leaf sheath hairy at summit, throat, or collar, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades 1-2 cm wide, Leaf blades 2 or more cm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades more or less hairy, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Ligule a fringe of hairs, Inflorescence terminal, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or clus ter per stem or culm, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence branches more than 10 to numerous, Inflorescence branches 1-sided, Flowers bisexual, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 florets, Spikelet with 1 fertile floret and 1-2 sterile florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets secund, in rows on one side of rachis, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Glumes 3 nerved, Glumes 4-7 nerved, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma 5-7 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemma awnless, Lemma mucronate, very shortly beake d or awned, less than 1-2 mm, Lemma straight, Palea present, well developed, Palea longer than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.

Megathyrsus maximus, known as Guinea grass and green panic grass, is a large perennial bunch grass that is native to Africa and Yemen. It has been introduced in the tropics around the world. It has previously been called Urochloa maxima and Panicum maximum. It was moved to the genus Megathyrsus in 2003.