Distribution
Hungary, Ukraine

Native to: Afghanistan, Alabama, Alaska, Albania, Alberta, Algeria, Altay, Amur, Argentina Northeast, Argentina Northwest, Argentina South, Arizona, Arkansas, Assam, Austria, Azores, Bahamas, Baleares, Baltic States, Bangladesh, Belarus, Belgium, Bolivia, Borneo, Brazil South, British Columbia, Bulgaria, Buryatiya, California, Canary Is., Cape Provinces, Central European Rus, Chad, Chile Central, Chile North, Chile South, China North-Central, China South-Central, China Southeast, Chita, Colombia, Colorado, Connecticut, Corse, Costa Rica, Cuba, Cyprus, Czechoslovakia, Denmark, East Aegean Is., East European Russia, East Himalaya, Ecuador, Egypt, Ethiopia, Falkland Is., Finland, Florida, France, Free State, Føroyar, Georgia, Germany, Great Britain, Greece, Guatemala, Hainan, Hawaii, Hungary, Iceland, Illinois, India, Indiana, Inner Mongolia, Iowa, Iran, Iraq, Ireland, Irkutsk, Italy, Jamaica, Japan, Juan Fernández Is., Kamchatka, Kansas, Kazakhstan, Kentucky, Kenya, Khabarovsk, Kirgizstan, Korea, Krasnoyarsk, Kriti, Krym, Kuril Is., Labrador, Lebanon-Syria, Leeward Is., Libya, Louisiana, Madagascar, Madeira, Magadan, Maine, Manchuria, Manitoba, Masachusettes, Mauritania, Mauritius, Mexican Pacific Is., Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Michigan, Minnesota, Missouri, Mongolia, Montana, Morocco, Myanmar, Nebraska, Nepal, Netherlands, New Hampshire, New Jersey, New Mexico, New South Wales, New York, New Zealand North, New Zealand South, Newfoundland, North Carolina, North Caucasus, North Dakota, North European Russi, Northern Territory, Northwest European R, Northwest Territorie, Norway, Nova Scotia, Nunavut, Ohio, Oklahoma, Ontario, Oregon, Pakistan, Palestine, Paraguay, Pennsylvania, Peru, Philippines, Poland, Portugal, Primorye, Prince Edward I., Qinghai, Queensland, Québec, Rhode I., Romania, Rwanda, Sakhalin, Sardegna, Saskatchewan, Sicilia, Sinai, Socotra, South Australia, South Dakota, South European Russi, Spain, Sri Lanka, Sudan, Sweden, Switzerland, Tadzhikistan, Taiwan, Tasmania, Tennessee, Texas, Thailand, Tibet, Transcaucasus, Tristan da Cunha, Tunisia, Turkey, Turkey-in-Europe, Turkmenistan, Tuva, Uganda, Ukraine, Uruguay, Uzbekistan, Venezuela, Vermont, Victoria, Vietnam, Virginia, Washington, West Himalaya, West Siberia, West Virginia, Western Australia, Wisconsin, Wyoming, Xinjiang, Yakutskiya, Yemen, Yugoslavia.

Herbs, annual, cespitose, 0.5-4 dm. Culms 1-many, occasionally becoming decumbent. Cataphylls 0-2. Leaves basal and cauline; auricles rudimentary or absent; blade flat, 3-13 cm x 0.3-1.1 mm. Inflorescences loose and diffuse or less often compact, usually at least ½ total height of plant; primary bract shorter than inflorescence. Flowers: bracteoles 2; tepals greenish, lanceolate, 3.8-7(-8.5) mm; inner series slightly shorter, apex sometimes obtuse; stamens 3-6, filaments (0.7-)1-1.8 mm, anthers 0.3-0.8 mm; style 0.1-0.2 mm. Capsules tan to reddish brown, 3-locular, ellipsoid to narrowly so, slightly truncate, 2.7-4 x 1-1.5 mm, sometimes exceeding inner tepals but usually not outer series. Seeds yellowish, widely ellipsoid to ovoid, 0.26-0.49, not tailed. 2n = 27-37, 58-81, 108-115.
Flowering and fruiting spring-early fall. Moist soils in meadows, along lakeshores or stream banks, ditches, or roadsides, especially frequent in drawdown areas; usually in open sites and often becoming weedy.