Medicago polymorpha L., Fabaceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Risk assessment results:  Reject, score: 11 (Go to the risk assessment).

Other Latin names:  Medicago hispida Gaertn.

Common name(s): [more details]

Chinese: nan mu xu

English: California bur-clover, bur clover, bur trefoil, burr medic, hairy medic, toothed bur-clover, toothed medic, toothed medick, trefoil-clover

French: luzerne hérissée, luzerne polymorphe

Japanese: uma-goyashi

Korean: gaejari

Spanish: carretón de amores, trébol de carretilla, trefol de carretilla

Habit:  herb

Description:  "Annual herbs; stems prostrate, up to 4 dm long, branched, subglabrous, with a few long hairs on petiolules, lower surface of leaflets, and calyx.  Leaflets obovate-cuneate, 7-25 mm long, 5-23 mm wide, glabrate, margins dentate in upper half, apex rounded to truncate or emarginate, stipules narrowly elliptic to narrowly ovate, laciniate.  Flowers (1-) 3-5 (-8) in racemes; corolla yellow, 3-4.5 mm long.  Pods 4-8 (-10) mm in diameter, spirally twisted in (1.5-) 3-4 (-6) turns, glabrous or subglabrous, transverse veins prominent, anastomosing, groove between submarginal and marginal vein wide, with nearly straight prickles 2-3 mm long, arising from the submarginal and marginal veins.  Seeds several"  (Wagner et al., 1999; pp. 684, 1878).

Habitat/ecology:  In Hawai‘i, "naturalized in open, dry to occasionally mesic, disturbed areas such as pastures, roadsides and vacant lots, 0-1,220 m" (Wagner et al., 1999; p. 684).  In Tonga, "uncommon in waste places" (Whistler, 1988; p. 28). In New Caledonia, "peu commun et vu surtout comme mauvaise herbe des gazons" (MacKee, 1994; p. 86).

Propagation:  Seed

Native range:  "Europe and temperate Asia to china and Japan, also in northern India, widely cultivated as a fodder plant" (Wagner et al., 1999; p. 684).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	introduced	Pickard, J. (1984) (p. 206) var. vulgaris
Australia (Pacific offshore islands) Lord Howe Island	Lord Howe Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 19) Vouchers cited: G. Uhe 1306 (K); L.A.S. Johnson & A.N. Rodd 1209 (K, NSW); J. Pickard 2660 (NSW); 1898, J.H. Maiden (NSW)
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive	Orchard, Anthony E., ed. (1994) (p. 9) Vouchers cited: G. Uhe 1145 (K); 1898 & 1902, I. Robinson (NSW)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced invasive	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Más a Tierra (Robinson Crusoe Island)	introduced invasive	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 555)
Chile (offshore islands) Juan Fernández Islands	Isla Más Afuera (Alejandro Selkirk Island)	introduced invasive	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Más Afuera (Alejandro Selkirk Island)	introduced invasive	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 555)
Chile (offshore islands) Juan Fernández Islands	Isla Santa Clara	introduced invasive	Atkinson, Rachel/Sawyer, John (2011)
Chile (offshore islands) Juan Fernández Islands	Isla Santa Clara	introduced invasive	Danton, Philippe/Perrier, Christophe/Martinez Reyes, Guido (2006) (p. 555)
Guam Guam Island	Guam Island	introduced	Stone, Benjamin C. (1970) (p. 337) var. vulgaris. Recent presence not confirmed.
Guam Guam Island	Guam Island	introduced	Fosberg, F. R./Sachet, Marie-Hélène/Oliver, Royce (1979) (p. 114) var. vulgaris per Stone. Recent presence not confirmed.
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 684) Voucher cited: Rock 3199 (BISH)
State of Hawaii Hawaiian Islands	Kaua‘i Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 684)
State of Hawaii Hawaiian Islands	Kure Atoll	introduced	Starr, Forest/Martz, Kim/Loope, Lloyd (2001) (p. 14) Previously reported, not observed in this survey.
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 684)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 684)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Herbst, Derral R./Wagner, Warren L. (1996) (p. 14) Voucher cited: Degener 3514 (US)
State of Hawaii Hawaiian Islands	O‘ahu Island	introduced invasive cultivated	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 684) Voucher cited: Forbes s. n. (BISH)
Japan (offshore islands) Ogasawara (Bonin) Islands	Bonin (Ogasawara) Islands	introduced	Kato, Hidetoshi (2007) Also var. confinis (W.D.J.Koch) Ooststr. et Reichg.
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	Tassin, Jacques (2005)
New Caledonia New Caledonia Archipelago	Île Grande Terre	introduced invasive	MacKee, H. S. (1994) (p. 86) Vouchers cited: Pancher s.n., MacKee 5195, Déméné in MacKee 14642, MacKee 37330
New Zealand (offshore islands) Kermadec Islands	Raoul Island	introduced invasive	Sykes, W. R. (1977) (p. 125)
Tonga Tonga Islands	Tonga Islands		Whistler, W. A. (1988) (p. 26)
United States (other Pacific offshore islands) Midway Atoll	Midway Atoll	introduced invasive	Bruegmann, Marie M. (1999) (p. 2) Voucher cited: Bruegmann 2013 (BISH)

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)	New South Wales	introduced invasive	National Herbarium of New South Wales (2013) Naturalised
Australia Australia (continental)	Australia (continental)	introduced invasive	National Herbarium of New South Wales (2013) South Australia, Tasmania, Victoria, Western Australia Naturalised
Australia Australia (continental)	Northern Territory	introduced invasive	National Herbarium of New South Wales (2013) Naturalised
Australia Australia (continental)	Queensland	introduced invasive	National Herbarium of New South Wales (2013) Naturalised
British Columbia (province of Canada) Province of British Columbia	Canada (British Columbia)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
Central America Central America (Pacific rim)	Costa Rica (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
Central America Central America (Pacific rim)	Guatemala (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
China China	China (People's Republic of)	introduced invasive cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Cultivated or escaped to fields, hillsides, and roadsides. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Sichuan, Yunnan, Zhejiang.
China China	Hong Kong	introduced cultivated	Wu, Te-lin (2001) (p. 149)
Japan Japan	Japan	introduced	Mito, Toshikazu/Uesugi, Tetsuro (2004) (p. 185) var. polymorpha, var. confinis (W.D.J. Koch), var. lapponica Burnet and var. microdon (Ehr.)
Mexico Mexico	Mexico (United Mexican States)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Adventive
South America (Pacific rim) South America (Pacific rim)	Chile (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
South America (Pacific rim) South America (Pacific rim)	Ecuador (Republic of) (continental)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
South America (Pacific rim) South America (Pacific rim)	Perú (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
Taiwan Taiwan Island	Taiwan Island	introduced invasive cultivated	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013) Cultivated or escaped to fields, hillsides, and roadsides.
United States (west coast) United States (west coast states)	USA (Oregon)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (west coast) United States (west coast states)	USA (California)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (west coast) United States (west coast states)	USA (Washington)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
Vietnam Vietnam	Vietnam (Socialist Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Canada Canada	Canada	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (continental except west coast) United States (other states)	United States (other states)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (continental except west coast) United States (other states)	USA (Florida)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Control:  If you know of control methods for Medicago polymorpha, please let us know.