Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: Grisebach's bristlegrass

Habit:  grass

Description:  "Plants annual. Culms 30-100 cm; nodes pubescent, hairs appressed. Sheaths with ciliate margins; ligules ciliate; blades to 12(25) cm long, to 10(20) mm wide, flat, hispid on both surfaces. Panicles 3-18 cm, loosely spicate, interrupted, often purple; rachises hispid; bristles 1-3, 5-15 mm, flexible, antrorsely scabrous. Spikelets 1.5-2.2 mm. Lower glumes about 1/3 as long as the spikelets, distinctly 3-veined, lateral veins coalescing with the central veins below the apices; upper glumes nearly equaling the upper lemmas, obtuse, 5-veined; lower lemmas equaling the upper lemmas; lower paleas about 1/3 as long as the lower lemmas, narrow; upper lemmas finely and transversely rugose; upper paleas similar to the upper lemmas" (Manual of Grasses for North America: Grass Manual on the Web).

Description from GrassBase.

Habitat/ecology:  "It grows in open ground" (Manual of Grasses for North America: Grass Manual on the Web).

Propagation:  Seed

Native range:  United States, Mexico, Belize, Colombia, Ecuador (GRIN).

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) Isabela Group	Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) Isabela Group	Volcán Cerro Azul, Isabela Island	introduced invasive	Charles Darwin Foundation (2008)
Ecuador (Galápagos Islands) San Cristóbal Group	San Cristóbal Island	introduced invasive	Charles Darwin Foundation (2008)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Colombia Colombia	Colombia (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Ecuador (Mainland) Ecuador	Ecuador (Republic of) (continental)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
Mexico Mexico	Mexico (United Mexican States)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
United States (continental except west coast) United States (other states)	United States (other states)	native	U.S. Dept. Agr., Agr. Res. Serv. (2011)
United States (continental except west coast) United States (other states)	United States (other states)	native	Utah State University (2004)

Comments:  Probably not native to the Galápagos Islands, possibly introduced, per Charles Darwin Research Station.

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

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

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

References:

Charles Darwin Foundation. 2008. Database inventory of introduced plant species in the rural and urban zones of Galapagos. Charles Darwin Foundation, Galapagos, Ecuador.

Charles Darwin Research Station. 2005. CDRS Herbarium records.

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

Utah State University. 2004. Manual of Grasses for North America: Grass Manual on the Web.