- Name also: Red Catchfly (USA)
- Family: Pink Family – Caryophyllaceae
- Growing form: Perennial herb.
- Height: 20–60 cm (8–25 in.). Stem ascending–erect, unbranched–sparsely branched, with long and soft hairs, upper part dark red.
- Flower: Plant dioecious (pistillate and staminate flowers on different plants). Corolla regular (actinomorphic), red (occasionally white), approx. 2–3 cm (0.8–1.2 in.) broad; petals 5, tip 2-lobed. Corolla mouth with small, lobed corona. Calyx fused, 5-lobed, with soft, glandular hairs, staminate flower narrow and approx. 10-veined, pistillate flower oval at base and approx. 20-veined. Stamens 10. Gynoecium syncarpous, with 5 styles. Inflorescence 3–20-flowered. Flowers lacking fragrance.
- Leaves: Opposite, basal leaves and lowest stem leaves long-stalked, uppermost stem leaves stalkless. Blade ovately elliptic–narrowly obovate, with entire margins, soft-haired.
- Fruit: Quite roundly barrel-shaped, golden brown, 9–14 mm (0.36–0.56 in.) long, 10-lobed capsule.
- Habitat: Seashore and stream bank alder groves, broad-leaved forests, coppices, river banks, forest margins, yards, banks, wasteland, fell precipices. Also an ornamental.
- Flowering time: (May–)June–August.
Red campion never grows in very dry places. Like many other Pink family members that grow on extremely alkaline serpentine rock it has developed its own hairy, low, narrow-leaved and small-flowered form.
Red campion’s most typical original habitats are sea-shore alder groves, and it is the type species for this environment. From sea-shore broad-leaved forests it has also escaped to land influenced by humans. It didn’t spread inland until the 20th century with the popularization of summer grain, but nowadays it is one of the most common herbs on meadows, banks, yards, and different kinds of local woods. Its beautiful, long-lasting flowers have made it many people’s favourite flower and it is often transplanted into gardens for decoration. It grows wild in Kilpisjärvi’s forest zone on rich meadows and stream banks, on fell slopes in the birch forest zone, and it even grows, albeit very rarely, in tundra regions.
Red campion flowers during the day and its most important pollinators are day butterflies, bees, and flower flies with long proboscises. Its close relative white campion (S. latifolia) opens its flowers at night and is pollinated by night butterflies, but the species also share pollinators and therefore cross-breed with each other. The hybrid is hairy and pink-flowered. Red campion’s rare white-flowered form is possible to differentiate from white campion by its shorter, partly glandular hair covering.
Sweet William Catchfly, Garden Catchfly
Annual Sweet William catchfly looks a lot like red campion, but is bit smaller, flowers are more densely an its calyx is glabrous (red campion’s is hairy). In Finland Sweet William catchfly is cultivated as an ornamental and can escape into the wild in suitable habitats.