- Family: Pink Family – Caryophyllaceae
- Growing form: Perennial herb. Forming mat-like stands.
- Height: 10–30 cm (4–12 in.). With many stems. Stem limp–ascending, woody at base, glabrous.
- Flower: Corolla regular (actinomorphic), white–violet, approx. 2.5–3 cm (1–1.2 in.) wide, petals 5, tips deeply 2-lobed. Corolla mouth with lobed corona (an additional small corolla). Calyx fused, oval, 5-lobed, net-veined. Stamens 10. Gynoecium syncarpous, with five styles. Flowers 1–5, erect; uppermost subtending bracts green–reddish, with membranous margins at most.
- Leaves: Opposite, stalkless. Blade lanceolate, fleshy, glabrous, wax-covered, bluish green.
- Fruit: 6–10 mm (0.25–0.4 in.) long capsule splitting into 5 lobes, teeth recurved.
- Habitat: Sandy, gravelly and stony seashores, rocky seashore crevices.
- Flowering time: July–August.
Sea campion is a real coastal plant which thrives in open, sandy shores along the coastline of the Gulf of Finland. On the other hand it can be found growing quite far inland, but in that case almost without exception on extremely alkaline rocks. Like certain other genus Silene plants it sometimes grows beside heavily salted highways. Its abundant flowers and undemanding nature also make it a favourite rockery perennial. It is a great addition to a butterfly garden too as its flowers are highly attractive to insects.
Sea campion was formerly known as bladder campion (S. vulgaris): apart from typical sea campion, other very close and similar-looking relatives can also be found all over its habitat, especially on the Åland Islands and the sea around the archipelago. The boundaries between different members of the Pink family have vacillated: pinks and campions have sometimes been counted together in a large group, or sometimes split into smaller units. Nowadays genus Silene includes both pinks and campions.
Sea campion is nowadays accepted as its own species, but it can be confused with bladder campion, especially (ssp. littoralis), which grows along seashores on the Gulf of Finland in places that sea campion doesn’t. Both species sometimes grow on the Åland Islands and the south-west archipelago. Bladder campion is usually more erect, has more flowers and has an unclear corona.