A European immigrant that has established itself all over eastern North America. It likes cultivated or recently disturbed ground; the one above was growing in a lot in Beechview that had recently been filled in, where it was blooming in late June. It also goes by the name of Evening Lychnis, because its flowers are nocturnal, closing during the day unless the weather is dreary, as it was on the rainy day when this picture was taken.
The taxonomy of this species is in a dreadful state. In published works we find it listed under a wide variety of names, some of them confusingly similar to the names of confusingly similar species. Older botanists place this species in the genus Lychnis, which differs from Silene in very small structural details of the flowers—so small, apparently, that botanists have now decided to disband the genus, absorbing its members into Silene. Thus in Gray this species is Lychnis alba; but Gray also records Silene latifolia as a synonym for S. vulgaris, the Bladder Campion. Other botanists record this species as Silene alba.
In an earlier version of this article, we gave the name as Silene latifolia subspecies alba, but the Flora of North America page on Silene Latifolia tells us that “most of our material tends to be intermediate, making recognition of subspecies here of little value. Presumably there has been extensive gene exchange between populations of this outbreeding species since its introduction into North America.” In other words, don’t bother trying to figure out subspecies. Good enough for us.
We give the description from the Flora of North America article on Silene latifolia, which is licensed under a Creative Commons Attribution 4.0 International deed.
Plants annual or short-lived perennial; taproot woody. Stems erect or decumbent at base, branched, to 100 cm, finely hirsute, glandular-puberulent distally. Leaves: blade hirsute on both surfaces; basal usually withering by flowering time, petiolate, blade oblong-lanceolate to elliptic; cauline sessile, reduced into inflorescence, blade lanceolate to elliptic, 3–12 cm × 6–30 mm, apex acute. Inflorescences several–many-flowered (fewer in pistillate plants), open, dichasial cymes, bracteate; bracts much reduced, lanceolate, herbaceous. Pedicels 1–5 cm. Flowers unisexual, some plants having only staminate flowers, others having only pistillate flowers, fragrant, 25–35 mm diam.; in veined staminate plants subsessile to short-pedicellate, in pistillate plants pedicellate; calyx prominently 10-veined in staminate flowers, 20-veined in pistillate, tubular, becoming ovate in pistillate flowers, 10–20(–24) × 8–15 mm in fruit, margins dentate, hirsute and shortly glandular-pubescent, lobes to 6 mm, broadly ovate with apex obtuse, to lanceolate with apex acuminate; petals white, broadly obovate, ca. 2 times calyx, limb spreading, unlobed to 2-lobed; stamens equaling to slightly longer than calyx; stigmas (4–)5, slightly longer than calyx. Capsules ovate, ca. equaling calyx, opening by (4–)5, spreading to slightly reflexed, 2-fid teeth; carpophore 1–2 mm. Seeds dark gray-brown, reniform-rotund, plump, ca. 1.5 mm, coarsely tuberculate. 2n = 24.
Phenology: Flowering summer–fall.
Habitat: Arable land, roadsides, waste land
Elevation: 0-2800 m