- Latin synonym: Atocion rupestre
- Family: Pink Family – Caryophyllaceae
- Growing form: Annual or sometimes perennial herb.
- Height: 10–20 cm (4–8 in.). Stem quite erect, branched from base, thin, glabrous.
- Flower: Corolla regular (actinomorphic), white, approx. 1 cm broad; petals 5, notched. Calyx fused, narrow, 5-lobed, glabrous, 10-veined, light brownish green. Mouth of corolla with unclear corona. Stamens 10. Gynoecium syncarpous, with 3 styles. Inflorescence many-flowered, lax.
- Leaves: Opposite, stalkless. Blade narrowly ovate–elliptic, with entire margins, bluish green, glabrous.
- Fruit: 4–6 mm (0.16–0.24 in.) long capsule.
- Habitat: Open rocks, precipices.
- Flowering time: July–August.
Delicate rock campion flowers bravely on thin layers of humus on dry rocks, where it is apt to be sun-baked and dry. It is very rarely that flowering plants thrive in such an extreme environment. Rock campion, however, is not a typical nectar plant: its best protection against dryness is a thin layer of wax which decreases evaporation and gives its leaves a bluish green colour. A lightly tufted way of growing affords this tenacious beauty a measure of protection against the harsh environment. Rock campion is remarkably able to cope with the hot sun, but in dry summers with long periods of good weather it turns the colour of straw, often in the middle of its flowering time.
The abundance of short-lived rock campion varies greatly from year to year and is dependent on the summer precipitation. It appears faithfully however on the same lichen rocks, while further south it doesn’t seem to spread well: rock campion’s habitat is characterized by a local concentration around which it is completely lacking over a broad area. The species avoids Finland’s most fertile rock species, but also many granite and gneiss rocks miss out on rock campion’s flowers. Perhaps the explanation can be found in the mists of time: The species’ habitats are usually so-called power hills that are higher than the surrounding land, i.e. the first hills to rise out of the sea. Rock campion lends some gaiety to the grey rocks mainly in southern and central Finland. In Kuusamo there are several separate stands around Rukatunturi Fell.
Delicate and slender rock campion can bring to mind Gypsophila plants which are also members of the Pink family as well as other Finnish campions and rock campions. Their gynoecium is however 2-bodied and the capsule is correspondingly only 4-lobed.