Polypogon viridis (Gouan) Breistr., Poaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Agrostis semiverticillata (Forssk.) C. Chr.

Common name(s): [more details]

English: beardless rabbitsfoot grass, water bent

French: agrostide demi-verticillée

Habit:  grass

Description:  "Perennials; culms strongly decumbent at base and rooting at nodes, (1.5-) 3-6 (-8) dm long.  Sheaths smooth, broad; ligule 1.5-4 (-6) mm long, truncate, erose-ciliolate and somewhat lacerate; blades flat, relatively wide, (1.5-) 2.5-4 (-7) mm long, upper surface smooth or scabrous.  Inflorescences paniculate, (2-) 4-10 (-16) cm long, compact, interrupted, the branches ascending to erect, spikelet-bearing to base; spikelets slightly laterally compressed, rachilla not prolonged; glumes small, subequal, (1.2-) 1.5-1.8 (-2) mm long, 1-nerved, densely and evenly scabrous, first glume ovate, second glume lanceolate; lemma membranous, 0.8-1.2 mm long, awnless, minutely apiculate by the excurrent nerves, callus blunt and glabrous; palea 0.5-1 mm long.  Caryopsis brown, cylindrical, 0.7-1 mm long, ca. 0.3 mm wide"  (Wagner et al., 1999; p. 1494).

Description from GrassBase.

Habitat/ecology:  In Hawai‘i, "naturalized in moist places, especially along steams, irrigation ditches, and seepage areas, 160-1,220 m"  (Wagner et al., 1999; p. 1494).

Propagation:  Seed

Native range:  "Native range unknown, occurring throughout the Old World tropics and in the Americas from Texas to Argentina" (Wagner et al., 1999; p. 1494). Macaronesia, northern Africa, Europe, western and central Asia; naturalized elsewhere (GRIN).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1494)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 1494) Vouchers cited: Knudsen s.n. (B), Mann & Brigham 273 (B)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia Australia (continental)	Australia (continental)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 124)
Mexico Mexico	Mexico (United Mexican States)		Hafliger, Ernst/Scholz, Hildemar (1980) (p. 124)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Edgar, E./Connor, H. (2000) (p. 289) "Lowland in waste ground, roadsides and edges of ditches, often in damp places, occasionally a garden weed".

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

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

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

Other Latin names:  Agrostis semiverticillata (Forssk.) C. Chr.

References:

Edgar, E./Connor, H. 2000. Flora of New Zealand, vol. V: Gramineae. Manaaki Whenua Press. .

Hafliger, Ernst/Scholz, Hildemar. 1980. Grass weeds, vol. 2. CIBA-GEIGY Ltd., Basle, Switzerland. 137 pp. + plates.

U. S. Government. 2009. Integrated Taxonomic Information System (ITIS) (on-line resource).

U.S. Dept. Agr., Agr. Res. Serv. 2009. National Genetic Resources Program. Germplasm Resources Information Network (GRIN). Online searchable database.

Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. 1999. Manual of the flowering plants of Hawaii. Revised edition. Bernice P. Bishop Museum special publication. University of Hawai‘i Press/Bishop Museum Press, Honolulu. 1919 pp. (two volumes).