White campion (Silene alba) is a winter or summer annual, biennial or short-lived perennial that initially forms a basal rossette, subsequently producing a thick, erect , branched, leafy stem with hairy or downy foliage and white inflated (balloon-like) flowers. White campion is mainly a weed of grains and legume forage crops, and can also be found in other field and vegetable crops, nurseries, waste places, and roadsides. It is most commonly found in full sun and on rich, well-drained soils. This weed is found throughout most of North America, particularly in the eastern and north-central United States and southern Canada.
Reproduction of white campion is primarily by seed but cultivation can fragment plants and spread adventitious buds on root and stem segments. Seedlings emerge in mid to late spring and again in late summer. Young plants produce rosettes. Winter annual and biennial plants overwinter as basal rosettes. Stems are produced and reach maturity in summer. Flowers are produced from May to fall.
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Resource: Uva, Richard H., Joseph C. Neal, and Joseph M. DiTomaso. Weeds of the Northeast. Ithaca: Comstock Pub. Associates, 1997. Print.