Distribution
Austria, Hungary, Netherlands, Poland, Ukraine, United States of America (introduced)

Native to: Afghanistan, Albania, Algeria, Altay, Amur, Austria, Baleares, Baltic States, Belarus, Belgium, Bulgaria, Buryatiya, Central European Rus, China North-Central, China South-Central, China Southeast, Chita, Corse, Cyprus, Czechoslovakia, Denmark, East Aegean Is., East European Russia, East Himalaya, Egypt, Finland, France, Føroyar, Germany, Great Britain, Greece, Gulf States, Hungary, Iceland, India, Inner Mongolia, Iran, Iraq, Ireland, Irkutsk, Italy, Kamchatka, Kazakhstan, Khabarovsk, Kirgizstan, Korea, Krasnoyarsk, Kriti, Krym, Kuril Is., Lebanon-Syria, Libya, Magadan, Manchuria, Morocco, Nepal, Netherlands, North Caucasus, North European Russi, Northwest European R, Norway, Pakistan, Palestine, Poland, Portugal, Primorye, Qinghai, Romania, Sakhalin, Sardegna, Saudi Arabia, Sicilia, Sinai, South European Russi, Spain, Sweden, Switzerland, Tadzhikistan, Tibet, Transcaucasus, Tunisia, Turkey, Turkey-in-Europe, Turkmenistan, Tuva, Ukraine, Uzbekistan, West Himalaya, West Siberia, Xinjiang, Yakutskiya, Yemen, Yugoslavia.
Introduced into: Alabama, Alaska, Alberta, Aleutian Is., Argentina Northeast, Argentina Northwest, Argentina South, Arizona, Arkansas, Bangladesh, Bermuda, Bolivia, Brazil South, Brazil Southeast, British Columbia, Burundi, California, Canary Is., Cape Provinces, Chile Central, Chile North, Chile South, Colombia, Colorado, Connecticut, Crozet Is., Cuba, Delaware, District of Columbia, Djibouti, Dominican Republic, Easter Is., Ecuador, El Salvador, Eritrea, Ethiopia, Falkland Is., Florida, Free State, Galápagos, Georgia, Greenland, Guatemala, Gulf of Guinea Is., Hainan, Haiti, Honduras, Idaho, Illinois, Indiana, Iowa, Jamaica, Japan, Kansas, Kentucky, Kenya, Kerguelen, KwaZulu-Natal, Labrador, Lesotho, Louisiana, Madeira, Maine, Manitoba, Maryland, Masachusettes, Mauritius, Mexican Pacific Is., Mexico Central, Mexico Northwest, Mexico Southwest, Michigan, Minnesota, Mississippi, Missouri, Montana, Namibia, Nebraska, Nevada, New Brunswick, New Hampshire, New Jersey, New Mexico, New York, New Zealand North, Newfoundland, Norfolk Is., North Carolina, North Dakota, Northern Provinces, Northwest Territorie, Nova Scotia, Nunavut, Ogasawara-shoto, Ohio, Oklahoma, Ontario, Oregon, Pennsylvania, Peru, Québec, Rhode I., Rwanda, Réunion, Saskatchewan, Socotra, South Carolina, South Dakota, South Georgia, Sri Lanka, St.Helena, Sudan, Svalbard, Taiwan, Tanzania, Tennessee, Texas, Uganda, Uruguay, Utah, Vermont, Vietnam, Virginia, Washington, West Virginia, Western Australia, Wisconsin, Wyoming, Yukon, Zaïre, Zimbabwe.

Plants mostly sparsely to densely pubescent, trichomes sessile, 3–5-rayed, stellate (base of plant often mixed with much longer, simple ones). Stems (0.2–)1–5(–7) dm. Basal leaves: petiole 0.5–4(–6) cm; blade oblong or oblanceolate, (0.5–)1.5–10(–15) cm × 2–25(–50) mm, base cuneate or attenuate, apex acute or acuminate. Cauline leaves: blade narrowly oblong, lanceolate, or linear, 1–5.5(–8) cm × 1–15(–20) mm, base sagittate, amplexicaul, or, rarely, auriculate. Fruiting pedicels usually straight, (0.3–)0.5–1.5(–2) cm, glabrous. Flowers: sepals green or reddish, 1.5–2 × 0.7–1 mm (margins membranous); petals (1.5–)2–4(–5) × 1–1.5 mm; filaments 1–2 mm; anthers to 0.5 mm. Fruits (0.3–)0.4–0.9(–1) cm × (2–)3–7(–9) mm, base cuneate, apex emarginate or truncate; valves each with subparallel lateral veins; style 0.2–0.7 mm. Seeds brown, 0.9–1.1 × 0.4–0.6 mm. 2n = 32.

Phenology: Flowering and fruiting Jan-Oct.
Habitat: Roadsides, gardens, fields, barren gravel, pastures, plantations, lawns, orchards, cultivated ground, waste areas, vineyards, mountain slopes.
Elevation: 0-2800 m.

(Flora of North America)