- Family: Pink Family – Caryophyllaceae
- Growing form: Perennial herb. Cushion-like, tufted.
- Height: 5–8 cm (2–3.2 in.).
- Flower: Corolla regular (actinomorphic), pink (occasionally white), approx. (0.5–)1–1.5 cm ((0.2–0.4–0.6 in.) broad; petals 5, notched. Calyx fused, narrow, 5-lobed, purplish. Corolla mouth with small, lobed corona. Flowers annual or bisexual. Stamens 10. Gynoecium syncarpous, with 3 styles. Flowers solitary, weakly fragrant.
- Leaves: Opposite, stalkless. Blade needle-like, linear, with entire but hairy margins, bright green, 6–12 mm (0.24–0.48 in.) long.
- Fruit: 6–11 mm long capsule.
- Habitat: Fell tundra stony ridges, moors, snow-bed sites, forest belt sandy lake and river shores. Calciphile.
- Flowering time: July–August.
Moss campion has adapted well to life on the wind-whipped slopes of the fell tundra. Its prostrate, compact tussock collects the heat of the sun but protects the plant from drying winds and frost. It can live for decades and grow noticeably large – a cushion up to half a metre wide might have come from a single seed and be anchored into the ground by a single taproot.
A bright green hummock of moss campion stands out well against the prevailing bare brown land even when it is not flowering, but in full bloom there is no way that anyone can miss it. Every stem in the dense tussock is terminated by a flower and eventually the whole plant is covered. People who live in the north have noticed the significance of the sun with regards to moss campion’s flowering: a tussock’s southern side might be in full bloom while on its northern side the buds are just pushing through: thus moss campion is a living tundra compass! Of the species’ flowers, some are large bisexual or staminate flowers and some are smaller pistillate flowers. Moss campion must cross-pollinate in order to form seeds, and it contains a lot of nectar to attract insects. This nectar lies down deep in the flower, however, and can only be reached by bees and butterflies which have long proboscises.
Moss campion doesn’t grow on Finland’s southernmost fells: its first stands are on stream banks and snow-bed sites on the Saariselkä and Pallas fells. It grows rarely in the coniferous forest belt on sandbanks in Inari Lapland. The species is only common however on the tundra of the large fells in the north-west “arm” of Finland, where it grows on fell heaths, rocky outcrops and gravelly slopes too. Moss campion can be confused with purple saxifrage (Saxifraga oppositifolia), which forms mat-like and tufted stands and flowers abundantly. Its leaves are however scaly and closer inspection reveals differences in the flowers.