- Name also: Dwarf Buttercup
- Family: Buttercup Family – Ranunculaceae
- Growing form: Perennial herb.
- Height: 2–10 cm (0.8–4 in.). Stems 1–4, limp–erect, unbranched, almost glabrous.
- Flower: Corolla regular (actinomorphic), pale yellow, usually 5–8 mm (0.2–0.32 in.) wide; petals 5, slightly shorter than sepals. Sepals 5, sparsely light-haired, withering early. Receptacle 1.5–5 mm (0.06–0.2 in.) long, glabrous or with hairy tip. Stamens many. Gynoecium separate leaves, with many pistils. Flowers solitary, flower-stalk densely haired.
- Leaves: Alternate, basal leaves 2–6, long-stalked, stem leaves usually stalkless. Basal leaf blades kidney-shaped, 3(–5)-lobed, central lobe usually entire, lateral lobes 2–3-lobed. Stem leaves 3-lobed, lobes narrowly obovate, with entire margins.
- Fruit: Achene, tip usually with under 0.5 mm (0.02 in.) long, thin, curved bristle. Achenes often together.
- Habitat: Fell tundra snow-bed sites, stream banks, springs, wet rock surfaces, wet Lappish slopes, gravels.
- Flowering time: July–August.
Pygmy buttercup is a hardy species that inhabits Finland’s highest fells. It is only common in Finland to any extent among the north-western fells of Enontekiö and is very rare in northern Utsjoki and along the River Tenojoki. Its southernmost stands are on the fells of Pallastunturi. It favours the upper tundra and avoids only the very highest peaks. Pygmy buttercup’s habitat includes stream banks in snow-bed sites, springs and rock surfaces that are kept wet by ice-cold meltwater.
Pygmy buttercup grows in places where metres of snow piles up in the winter, protecting the frost-sensitive plant underneath. It only shows its face at the end of the summer so it has a very short growing season. It is fast-growing and has adapted well so it can even thrive in places where the snow melts late, where other vascular plants cannot live. It is surrounded by just moss and algae. Pygmy buttercup’s life cycle is frantic, despite the chilly climate it inhabits: it already opens its first flower only days after the snow has melted and the seeds ripen in a month. This speed is a great boon to the plant, helping it fulfil its cycle before the next snow falls. Unlike most other fell tundra plants, pygmy buttercup doesn’t propagate vegetatively, although it can divide into two plants when its root branches.