Potentilla nivea -group
- Name also: Snowy Cinquefoil (Potentilla nivea), Bluff Cinquefoil (Potentilla arenosa)
- Family: Rose Family – Rosaceae
- Growing form: Perennial herb. Rhizomatous.
- Height: 5–20 cm (2–8 in.) (P. nivea) or 15–30 cm (6–12 in.) (P. arenosa). Stem ascending, hairy, often reddish.
- Flower: Corolla regular (actinomorphic), yellow, 1–2 cm (0.4–0.8 in.) broad; petals five, 6–9 mm (0.24–0.36 in.) long, slightly longer than calyx lobes. Calyx 5-lobed; with epicalyx. Stamens 10–30. Gynoecium separate, pistils many. Inflorescence narrow, 2–8-flowered corymb.
- Leaves: Basal leaves long-stalked, stem leaves alternate, short-stalked–stalkless, stipulate. Leaflets 3 (sometimes 5), terminal leaflet sometimes stalked (P. arenosa). Leaflets elliptic–obovate, with short and blunt teeth until base, teeth 9–13 (P. nivea) or with long and tapered teeth, teeth 5–9 (P. arenosa), green on top, underside densely white-haired.
- Fruit: Receptacle bears many shallow-tipped achenes.
- Habitat: Rocky embankments on fells and in canyons, crags, steep Lappish rock faces, scree beds. Calciphile.
- Flowering time: July–August.
- Endangerment: Both subspecies are near threatened and protected in all of Finland.
Snow cinquefoil grows in two areas of Finland: it grows in the northern Lappish fell tundra, but there is also a separate stand on ravine walls in Kuusamo. After the Ice Age snow cinquefoil followed the retreating ice along with other tundra plants and found a home on the emerging soil under the ice sheet. When forests and bogs took over after the Ice Age the plant fled north and has survived in the south only in especially favourable places. The walls and gorges of the Oulanka and Kitka river valleys have provided a refuge for a number of rare plants as living reminders of a time when the whole land was tundra some ten thousand years ago.
Snow cinquefoil propagates apomictically i.e. from seed but without fertilization, so its ancestors all look the same as the mother plant. It’s typical of plants that reproduce apomictically that there are many lineages with only slight differences, i.e. micro-species. Snow cinquefoil is sometimes divided into a number of species, but nowadays micro-species are considered to be subspecies. The broad subspecies Svalbard snow cinquefoil (ssp. nivea) grows in the ravines of Kuusamo, close to Takkaselkä Fell, the large Käsivarsi fells, and the canyons of River Kevojoki in Utsjoki.
Bluff cinquefoil grows in Kuusamo, in several places in the Käsivarsi fells and in Utsjoki. Svalbard snow cinquefoil is the smaller of the two and its leaf stems are fuzzy-haired. Also, its leaflets are clearly broadly elliptic, with more and blunter teeth. Both subspecies are calciphilous and sometimes grow side by side. It can sometimes be difficult to differentiate between the two subspecies because they have features of both Svalbard snow cinquefoil and bluff cinquefoil. Alpine cinquefoil (P. crantzii), which is much more common in the same places, is not felt-haired on its underside.