Thlaspi arvense L., Brassicaceae

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Present on Pacific Islands?  no

Primarily a threat at high elevations?  no

Risk assessment results:  High risk, score: 19 (Go to the risk assessment)

Common name(s): [more details]

Chinese: xi ming

English: Frenchweed, Mithridate mustard, bastard cress, fanweed, field pennycress, pennycress, stinkweed, wild garlic

Habit:  herb

Description:  "Plants (sometimes glaucous), glabrous throughout. Stems (0.9-) 1.5-5.5 (-8) dm. Basal leaves not rosulate; petiole 0.5-3 cm; blade oblanceolate, spatulate, or obovate, 1-5 cm x 4-23 mm, base attenuate or cuneate, margins entire, repand, or coarsely dentate, apex rounded. Cauline leaves: blade oblong, (0.5-) 1.5-4 (-8) cm x (2-) 5-15 (-25) mm, apex rounded, obtuse, or subacute. Fruiting pedicels straight or slightly upcurved, (5-) 9-13 (-15) mm. Flowers: sepals (1.5-) 2-3 (-3.3) x 1-1.5 mm; petals (2.4-) 3-4.5 (-5) x (0.8-) 1.1-1.7 mm, narrowed to clawlike base (ca. 1 mm), apex obtuse or emarginate; filaments (1-) 1.5-2.2 mm; anthers 0.3-0.5 mm. Fruits obovate or suborbicular, (0.6-) 0.9-2 cm x (5-) 7-20 mm, base obtuse or rounded, apex deeply emarginate, notch ca. 5 mm deep; wings broad throughout, 1-1.5 mm wide basally, 3.5-5 mm wide apically; ovules 6-16 per ovary; style 0.1-0.3 mm. Seeds (1.2-) 1.6-2 (-2.3) x 1.1-1.3 mm, concentrically striate"  (Flora of North America online).

Habitat/ecology:  In the United States:  "Roadsides, fields, waste places, lawns, gardens, railroad tracks, stream banks, bluffs, thickets, slopes, floodplains, woods; 0-2000 m"  (Flora of North America online).  In China (native): "Roadsides, grassy slopes, fields, waste places; 100-5000 m"  (Flora of China online).

Propagation:  Seed

Native range:  Europe and Asia; naturalized elsewhere (GRIN).

Presence:

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) Weed of waste places.
Australia Australia (continental)	Australia (continental)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Victoria Naturalized
British Columbia (province of Canada) Province of British Columbia	Canada (British Columbia)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
China China	China (People's Republic of)	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
Japan Japan	Japan	native	U.S. Dept. Agr., Agr. Res. Serv. (2013) Hokkaido, Honshu, Kyushu, Shikoku
Japan Ryukyu Islands	Ryukyu Islands	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
North Korea North Korea	North Korea (Democratic People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South Korea South Korea	South Korea (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
New Zealand New Zealand	New Zealand (country)	introduced invasive	Webb, C. J./Sykes, W. R./Garnock-Jones, P. J. (1988) (p. 447) Arable fields, waste land.
South America (Pacific rim) South America (Pacific rim)	Chile (Republic of)	introduced invasive	U.S. Dept. Agr., Agr. Res. Serv. (2013) Naturalized
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)

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 Thlaspi arvense, please let us know.