White Campion is an erect annual to short-lived perennial introduced from Europe and naturalized, growing to 40 inches high on stems that have fine hair with glandular hair near the top. Stems branch freely.
The leaves are of two types: Leaves at the bottom of the stem are lance shaped, 5x as long as wide, hairy and tapering to a stalk. These are usually gone at flowering time. Stem leaves are opposite, with 6 to 9 pairs on the stem, hairy on both sides, smaller than the lower leaves and stalkless toward the top of the stem.
The inflorescence is composed of several many-flowered open clusters which have very small bracts and small stem leaves.
The flowers are stalked, 1 to 1-1/3 inches wide when open with 5 white spreading petals that are deeply 2-lobed but may occasionally be un-lobed. Plants are usually dioecious, that is, male and female flowers are on different plants. The calyx is tubular, usually hairy, with 10 prominent veins on male flowers and 20 veins on female flowers. Most calyx tubes are green with dark green veins, some have purplish veins, all with fine hair. Male flowers have 10 stamens, usually equal in length to the calyx. Female flowers have 5 styles, and are slightly longer than the calyx, which becomes inflated to ovoid shape after fertilization. Flowers are slightly fragrant, are open during the day, but may close in the afternoon.
Seed: Fertile flowers develop into a capsule with 5 valves that are 2-cleft at the apex, giving the appearance of 10 teeth. The numerous seeds are gray to bluish-brown, with warty bumps in concentric rows. When mature the valves at the top of the capsule reflex and the seeds are shaken out by the wind.
Habitat: White Campion is found in waste places and disturbed sites in various drier soil types and usually in partial shade. The plant grows from a woody taproot.
Names: The genus, Silene, is from the Greek word seilenos and believed to be derived from Silenus who was the foster father of the Greek god Bacchus. Silenus was described as covered with foam, a reference to the white foam frequently found on stems of this genus. The species, latifolia, is a Latin word applied to plants with wide to broad leaves. In former days this species was classified as Lychnis alba, however, North American members of the genus Lychnis have been reclassified into the genus Silene. The author name for the plant classification - ‘Poir.’ is for Jean Louis Marie Poiret (1755-1834) French clergyman, botanist and explorer and Professor of Natural History at the Ecoles Centrale of Aisne. The authoritative Flora of North America reports that some references mis-apply S. latifolia to Bladder Campion, whose correct name is S. vulgaris. Also, in Europe, botanists recognize several subspecies, but the plants in North America tend to be intermediate and subspecies are not recognized here.
Comparisons: There are several Silenes with white flowers that may be mistaken for this species. Night-flowering Catchfly, S. noctiflora, is quite similar but the female flowers have 3 styles and of course, the flowers open at night and close in the morning. Starry Campion, S. stellata, has frilly lobes on the petals and leaves in whorls. Evening Campion, S. nivea, has no rib-like veins on the calyx which is bell shaped. Royal Catchfly, Silene Regia, has a red corolla. S. vulgaris, Bladder Campion has a more pronounced inflated calyx with pinkish color and deeper pink veins.
Above: Drawing of White Campion by Norman Criddle, 1909.
Below: The open flowers have 5 white spreading petals that are deeply 2-lobed but may occasionally by un-lobed. Male (2nd photo) and female (1st photo) flowers are on different plants.
Below: 1st photo - The calyx tube has prominent veins which are purple on some plants and green on others. 2nd photo - A female flower of White Campion has 5 styles which are longer than the calyx tube.
Below: 1st photo - When a flower becomes fertilized the bladder inflates. 2nd photo - The lower leaves are stalked and 5x as long as wide.
Below: Upper stem leaves are stalkless. The upper stem and the stem of the flower cluster have glandular hair. The leaves have fine surface hair on both surfaces.
Below: 1st photo - Female flowers have 20 veins on the hairy calyx tube. 2nd photo - Male flowers have 10 veins on the hairy calyx tube. 3rd photo - The stamens of male flowers are no longer than the calyx tube.
Below: The seed capsule appears to have a number of triangular flanges at the top opening but there are 5 valves that each have a flange that is cleft into 2 parts at the apex. Each capsule contains up to 50+ small seeds that have rows of concentric bumps.
Notes: White Campion is a historical Garden plant. Eloise Butler planted the first one on June 12, 1916 with a plant sourced from "the vicinity of Savage" (MN). In 1938 Martha Crone noted the species blooming. It was present at the time of her 1951 census, but was missing on the 1986 census. White Campion has naturalized all across the U.S. except for 6 states in the far south. There are twelve Silenes found in Minnesota, 4 native and 8 not native; this species is one of 8 that is not native and is one of the most widespread, being absent mostly in the drier counties of the SW quadrant.
The Silenes native to Minnesota are: S. antirrhina, Sleepy Catchfly; S. drummondii, Drummond's Campion; S. nivea, Snowy Campion; and S. stellata, Starry Campion.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"