Pacific Island Ecosystems at Risk (PIER)

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Urochloa brizantha
(Hochst. ex A. Rich.) R. D. Webster, Poaceae
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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results: 

Evaluate, score: 4 (Go to the risk assessment).
See also risk assessment for Brachiaria brizantha Hochst Stapf x Brachiaria ruziziensis Germ. & Evr.

Other Latin names:  Brachiaria brizantha (Hochst. ex A. Rich.) Stapf; Panicum brizanthum (Hochst. ex A. Rich.)

Common name(s): [more details]

English: bread grass, palisade grass, palisade signalgrass, signal grass, Surinam grass

Spanish: pasto braquiaria, pasto mulato

Habit:  grass

Description:  "Tufted perennial; culms 30-200 cm high, erect or sometimes geniculately ascending.  Leaf-blades linear to broadly linear, 10-100 cm long, 3-20 mm wide.  Inflorescence of (1-) 2-16 racemes on an axis 3-20 cm long; racemes mostly 4-20 cm long, bearing the spikelets singly, these typically forming a single row; rhachis crescentic in section, ± 1 mm wide, with narrow inrolled wings, ciliate on the margins.  Spikelets plumply elliptic, 4-6 mm long, glabrous or sometimes sparsely pubescent, obtuse to subacute with a slight stipe at the base; lower glume 1/3 the length of the spikelet, clasping, acute or obtuse; upper glume cartilaginous, dully shining, separated from the lower by an internode; lower resembling the upper glume; upper lemma granulose, acute" (Clayton & Renvoize, 1982; p. 587).

"Culms erect, 60-120 cm high; leaf blades smooth, markedly nerved, 20-30 cm long, 6-18 mm broad; flowering culms bearing up to 4 racemes, these ascending, recurved, the rachis strong and narrow, usually deep purple in color; spikelets large, purple-tinged on margins, 4-6 mm long, the lower glume purple-tinged, less than half length of spikelet and clasping base of spikelet, the upper glume as long as spikelet, sparsely hairy toward apex" (Smith, 1979; p. 332).

"Perennial, up to over 6 ft. high from a short sometimes stout rhizome, with stout tomentose root-fibres and extravaginal or intravaginal innovations covered in bud by coriaceous glabrous and often shining or sometimes appressedly hairy cataphylls. Culms erect, rarely geniculately ascending, stout, 4-6-(or sometimes many-) noded, simple or scantily branched, upper internodes exserted. Leaves glabrous or softly hairy to almost velvety; sheaths rather tight, terete, firm, not persisting very long, striate; ligules a narrow fimbriate rim; blades linear or if short sometimes sublanceolate, acute or long-tapering to a slender point, 2-15 in. by 3-8 lin., usually flat, firm, light green, margins cartilaginous and spinulose, nerves numerous and very fine, the primary lateral more or less distinctly differentiated below, midrib channeled above, somewhat prominent underneath. Inflorescences secund, of 2-8 vary rarely solitary distant sessile straight or more often arching or falcate spike-like racemes; common axis 7-1 in. long, triquetrous or semiterete, glabrous, with seabrid or ciliolate rarely setulose angles. Racemes secund, dense, 2 to over 6 in. long, sometimes with one or more arrested spikelets at the apex, simple, usually 1-seriate with the spikelets superposed, occasionally partly 2-seriate; rhachis straight or wavy upwards, rather flat or convex on the back, concave on the face, up to over 1/2 lin. wide, seabrid and loosely ciliate along the angles, cilia rising from small tubercles along the margins, villosulous at the base, internodes 1 1/2-2 lin. long; pedicels solitary, very short, stout, usually sparingly setulose. Spikelets closely contiguous, oblong to elliptic-oblong, rather obtuse or subacute, turgid, 2-3 lin. long, glabrous rarely sparingly hairy upwards, pallid, frequently with purple tops or variously tinged with purple. Glumes very unequal, membranous to subchartaceous; the lower broad-ovate, obtuse, clasping, half the length of the spikelet or almost so, 7-11-nerved, often purple, glabrous, the upper glume corresponding in outline and size to the spikelet or slightly shorter, very convex, sometimes minutely apiculate, 7-9-nerved, with a few cross-veins near the tip, usually glabrous. Lower floret male, as long as the spikelet, similar to the lower glume, but flattened or depressed on the back, 5-nerved; valvule oblong, subobtuse, finely keeled, flaps rather broad; anthers 11/2 lin. long. Upper floret equaling the upper glume or as long as the spikelet, oblong in outline, sometimes with a short blunt incurved point, pale or slightly greenish; valve and valvule crustaceous, very delicately pitted, flaps of valvule very broad above the base" (Prain, 1934; pp. 531-533).

Description from GrassBase.

Habitat/ecology:  In Africa, "Deciduous woodland, wooded grassland and upland grassland; 300-2400 m" (Clayton & Renvoize, 1982; p. 587).

Propagation:  Seed

Native range:  "Tropical and South Africa; introduced elsewhere in the tropics" (Clayton & Renvoize, 1982; p. 587).

Presence:

Pacific
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Ecuador (Galápagos Islands)
San Cristóbal Group
San Cristóbal Island introduced
cultivated
Charles Darwin Foundation (2008)
Urochloa brizantha x ruziziensis
Fiji
Fiji Islands
Vanua Levu Island introduced
cultivated
Smith, Albert C. (1979) (p. 332)
Vouchers cited: DA 15293, DA 15296
Fiji
Fiji Islands
Viti Levu Island introduced
cultivated
Smith, Albert C. (1979) (p. 332)
Vouchers cited: DA 7459, DA 11778
State of Hawaii
Hawaiian Islands
Maui Island introduced
invasive
Oppenheimer, Hank (2008) (p. 31)
East Maui. Voucher cited: Oppenheimer & Hansen H90403 (BISH, PTBG)
State of Hawaii
Hawaiian Islands
O‘ahu Island introduced
cultivated
Starr, Forest/Starr, Kim/Loope, Lloyd L. (2006) (p. 39)
Voucher cited: Hosaka 2553 (BISH)
Samoa
Western Samoa Islands
Savai‘i Island   National Tropical Botanical Garden (U.S.A. Hawaii. Kalaheo.) (2002) (voucher ID: PTBG 274)
Taxon name on voucher: Urochloa brizantha
Pacific Rim
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
China
China
Hong Kong native
Wu, Te-lin (2001) (p. 328)
As Brachiaria brizantha (Hochst. ex A. Rich) Stapf
Indian Ocean
Country/Terr./St. &
Island group
Location Cited status &
Cited as invasive &
Cited as cultivated &
Cited as aboriginal introduction?
Reference &
Comments
Australia (Indian Ocean offshore islands)
Cocos (Keeling) Islands
Cocos (Keeling) Islands introduced
invasive
Orchard, Anthony E., ed. (1993) (p. 38)

Comments:  Introduced into Fiji as a pasture grass, 1950 (Smith, 1979; p. 332). Present status not known.


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This page was created on 2 JAN 2004 and was last updated on 23 OCT 2010.