Urochloa humidicola (Rendle) Morrone & Zuloaga, Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  More information needed, score: 0 (Go to the risk assessment)

Other Latin names:  Brachiaria humidicola (Rendle) Schweickerdt

Common name(s): [more details]

English: creeping signal grass, koronivia grass

Habit:  grass

Description:  "Perennial, creeping, giving rise to a number of stolons with culms arising at intervals, these usually geniculately ascending, often rooting at nods, 45-90 cm high; leaf blades 6-15 cm long, 5-8 mm broad, glabrous; racemes 2-4, rarely more, 3.5-5 cm long, the rachis more or less flat; spikelets 3-4 mm long, elliptic to broadly elliptic; lemma of upper floret with an inconspicuous apiculus, usually pure white when mature" (Smith, 1979; p. 338).

"Habit: Perennial. Stolons present. Culms geniculately ascending, or decumbent; 40-100 cm long; without nodal roots, or rooting from lower nodes. Ligule a fringe of hairs. Leaf-blades linear, or lanceolate; 4-20 cm long; 3-10 mm wide. Inflorescence: Inflorescence composed of racemes. Racemes 2-3(-4); borne along a central axis; unilateral; 2-7 cm long. Central inflorescence axis 2-13 cm long. Rhachis wingless, or narrowly winged; angular. Spikelet packing adaxial; regular; 2-rowed. Spikelets solitary. Fertile spikelets sessile. Fertile spikelets: Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; compressed slightly; subacute; 4-6 mm long; falling entire. Rhachilla internodes elongated between glumes. Glumes: Glumes similar; reaching apex of florets; thinner than fertile lemma. Lower glume oblong; 0.75-1 times length of spikelet; membranous; without keels; 11-veined. Lower glume surface glabrous, or pubescent. Lower glume apex obtuse. Upper glume oblong; 1 times length of spikelet; membranous; without keels; 5-9-veined. Upper glume lateral veins with cross-veins. Upper glume surface glabrous, or pubescent. Upper glume apex obtuse. Florets: Basal sterile florets male; with palea. Lemma of lower sterile floret similar to upper glume; oblong; 1 times length of spikelet; membranous; 5-veined; with cross-veins; glabrous, or pubescent; obtuse. Fertile lemma elliptic; 3.5-5.5 mm long; indurate; without keel. Lemma surface papillose. Lemma margins involute. Lemma apex obtuse, or acute. Palea involute; indurate; without keels" (GrassBase).

Habitat/ecology:  In Fiji, "introduced as a pasture grass and now established in wet and intermediate zones" (Smith, 1979; p. 338).

Propagation:  Seed, locally by rooting from stolons.

Native range:  Africa (Smith, 1979; p. 338).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Fiji Fiji Islands	Vanua Levu Island	introduced invasive cultivated	Smith, Albert C. (1979) (p. 330) Voucher cited: DA 15389
Fiji Fiji Islands	Vanua Mbalavu Island	introduced invasive cultivated	Smith, Albert C. (1979) (p. 330) Voucher cited: Garnock-Jones 1083
French Polynesia Marquesas Islands	Nuku Hiva (Nukahiva) Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Cultivée
French Polynesia Society Islands	Tahiti Island	introduced cultivated	Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. (2011) Cultivée
New Caledonia New Caledonia	New Caledonia Islands	introduced cultivated	MacKee, H. S. (1994) (p. 58) "Dans les essais récents de plantes fourragères".
Niue Niue	Niue Island	introduced invasive	Space, James C./Waterhouse, Barbara M./Newfield, Melanie/Bull, Cate (2004) (p. Voucher specimens submitted for determination.) Specimens collected: BMW 7073 (BISH, CHR, BRI), BMW 7083 (BISH, CHR, BRI)
Solomon Islands Solomon Islands	Solomon Islands	introduced cultivated	Hancock, I. R./Henderson, C. P. (1988) (p. 52)

Additional information:
Additional online information about Urochloa humidicola is available from the Hawaiian Ecosystems at Risk project (HEAR).

Information about Urochloa humidicola as a weed (worldwide references) may be available from the Global Compendium of Weeds (GCW).

Taxonomic information about Urochloa humidicola may be available from the Germplasm Resources Information Network (GRIN).

References:

Clayton, W. D./Harman, K. T./Williamson, H. 2002. World Grass Species: Descriptions, Identification, and Information Retrieval (online resource).

Florence, J./Chevillotte, H./Ollier, C./Meyer, J.-Y. 2011. Base de données botaniques Nadeaud de l'Herbier de la Polynésie Française (PAP). (online resource).

Hancock, I. R./Henderson, C. P. 1988. Flora of the Solomon Islands. Research Bulletin No. 7. Ministry of Agriculture and Lands, Honiara. 203 pp.

MacKee, H. S. 1994. Catalogue des plantes introduites et cultivées en Nouvelle-Calédonie. Muséum National d'Histoire Naturelle, Paris, 164 p.

Smith, Albert C. 1979. Flora Vitiensis nova: a new flora of Fiji. National Tropical Botanical Garden, Lawai, Kauai, Hawaii. Volume 1. 494 pp.

Space, James C./Waterhouse, Barbara M./Newfield, Melanie/Bull, Cate. 2004. Report to the Government of Niue and the United Nations Development Programme: Invasive plant species on Niue following Cyclone Heta. UNDP NIU/98/G31 - Niue Enabling Activity. 80 pp.

Swarbrick, John T. 1997. Weeds of the Pacific Islands. Technical paper no. 209. South Pacific Commission, Noumea, New Caledonia. 124 pp.

U.S. Dept. Agr., Agr. Res. Serv. 2011. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.