Annual or short-lived perennial herb with a woody taproot 40 cm - 1 m tall Stem: decumbent at the base or upright, branched, finely hairy, glandular above. Inflorescence: a much-branched, open cluster (dichasial cyme) of several to many flowers, subtended by much-reduced bracts. Flowers: male or female (some plants having only one or the other), white, 2.5 - 3.5 cm in diameter, fragrant. Stalk upright, to 5 cm long. Stamens ten. Styles mostly five. The flowers open in the evening. Sepals: fused at the base into a tube (calyx). Calyx tube 1 - 3 cm long, 8 - 15 mm wide, tubular, becoming inflated and egg-shaped in female flowers, ten-veined (in male flowers), twenty-veined (in female flowers), hairy, shortly glandular, with five short lobes. Lobes to 6 mm long, and broadly egg-shaped with a blunt tip. Petals: five, white, 2 - 4 cm long, about two times as long as the calyx, broadly reverse egg-shaped, narrowly clawed, deeply two-lobed or unlobed. Fruit: a dehiscent capsule, opening by five (appearing as ten) upright teeth, 1 - 1.5 cm long, more or less equaling calyx, egg-shaped. Seeds dark grayish, about 1.5 mm long, kidney-shaped to rounded, plump, roughened. Basal leaves: often withering by flowering time, stalked, oblong lance-shaped to elliptic, and hairy. Stem leaves: opposite, up to ten pairs, stalkless, 3 - 12 cm long, 0.5 - 4 cm wide, lance-shaped to elliptic with a pointed tip, three- to five-veined, and hairy.
Similar species: No information at this time.
Flowering: May to early October
Habitat and ecology: Introduced from Eurasia. A very common weed in many habitats, such as waste ground, cultivated fields, pastures, and along railroads.
Occurence in the Chicago region: non-native
Etymology: Silene probably comes from the Greek word sialon, meaning saliva, referring to the sticky secretion on many of these plants. It may also have come from the word seilenos, referable to Silenus-a foam-covered, drunken character in Greek Mythology. Latifolia means "wide leaves." Alba means white.