Ranunculus acris -group
- Name also: Tall Buttercup
- Species: Ranunculus acris and Ranunculus subborealis
- Family: Buttercup Family – Ranunculaceae
- Growing form: Perennial herb. Rootstock short, quite erect.
- Height: 5–100 cm (2–40 in.). Stem erect, many-branched, hairy.
- Flower: Corolla regular (actinomorphic), golden-yellow, 12–25 mm (0.48–1 in.) wide; petals 5, longer than sepals. Sepals 5, parallel to corolla, hairy. Receptacle glabrous. Stamens many. Gynoecium separate, with many pistils. Inflorescence lax, cyme-like, 1–20-flowered, flower-stalks shiny.
- Leaves: Alternate, basal leaves long–short-stalked, stem leaves almost stalkless. Basal leaf blades roundish, 3–5(–9)-lobed, lobes varyingly twice-lobed–toothed, sharp-tipped. Stem leaf blades 3-lobed, lobes entire–irregularly large-toothed.
- Fruit: Glabrous, 2–3.5 mm long achene, tip with 0.2–0.8 mm (0.008–0.032 in.) long, curved bristle. Achenes in clusters.
- Habitat: Meadows, roadsides, banks, yards, young forests, broad-leaved forests, swamps, river banks, lake shores, fell meadows.
- Flowering time: June–September.
Meadow buttercup is a classic example in school text books and for that reason many people have been familiar with it since they were children. It is however a very diverse species which has developed different subspecies in different habitats. Its southern subspecies ssp. acris is very like the meadow buttercup that is familiar from nature trails. Its original habitats in Finland are the upper parts of sea shores and loamy riverside meadows. It is a stock herb on pasture land as cattle usually leave the poisonous plant alone. It is also unhealthy for humans. Ssp. friesianus can be found in parks and places with brisk traffic. There is also a cultivated garden plant, such as a form with a compound corolla which is sold in garden centres.
In the northernmost corners of the country there can be found a species belonging to Meadow buttercup-group. It has three subspecies: Ssp. borealis grows all the way north to riverside meadows and banks in Lapland and Kuusamo and looks slightly odd to the southern Finnish eye with its blunt leaflets and scant inflorescence. The same is true of densely brown-haired ssp. villosus. Low-growing, sturdy and usually one-flowered ssp. pumilus grows on Lappish fells does not really look much like its large and abundantly branched southern cousin.
A whole bunch of other buttercups that are often mistakenly taken for meadow buttercup can also be found in yards. Creeping buttercup (R. repens) is usually easy to recognise from its low height and stalked terminal leaflets. Handsomely flowering multiflowered buttecup (R. polyathemos) has leaves that are more lobed than meadow buttercup’s. Additionally, both species’ flower-stalks are grooved while meadow buttercup’s are glossy. When comparing to members of the apomictic goldilocks group (R. auricomus), good identifying markers are on the stem leaves: meadow buttercup’s are three-lobed, goldilocks’ leaves are 5–9-lobed.