Ranunculus aconitifolius is a herbaceous perennial that produces white flowers in spring, flowering from April to June. It reaches about 0.6 metres and performs best in moist, well-drained soil with full sun or partial shade. Native to Europe, it is suited to borders, woodland plantings and naturalising in damp ground. The plant is harmful if eaten and can irritate skin, so wear gloves when handling.

Fair Maids of France (Ranunculus aconitifolius) produces white flowers April to June and suits moist, part-shade borders and woodland gardens.

https://en.wikipedia.org/wiki/Ranunculus_aconitifolius

Ranunculus is a large genus of about 1750 species of flowering plants in the family Ranunculaceae. Members of the genus are known as buttercups, spearworts and water crowfoots.

Ranunculus aconitifolius

Fair maids of France | Ranunculus aconitifolius

Ranunculus aconitifolius 'Flore Pleno' is a herbaceous perennial that reaches about 0.6 metres and carries white spring flowers. It flowers from April to June and suits positions in full sun or partial shade. It prefers moist, well-drained soil and remains fully hardy in the UK (H7). Use it where consistent soil moisture can be maintained, particularly in borders or woodland plantings.

Ranunculus aconitifolius 'Flore Pleno' is a 0.6 metre perennial with white flowers April to June for moist, well‑drained borders and woodland gardens.

Ranunculus aconitifolius 'Flore Pleno'

Bachelor's Button | Ranunculus aconitifolius 'Flore Pleno'

Ranunculus acris 'Flore Pleno' is a perennial herb in the Ranunculaceae that produces upright stems to about 1.0 m. It flowers in April to June. It grows best in full sun and tolerates a wide range of soils from sandy to clay, preferring consistently moist ground. The plant is toxic and should not be grazed.

Buttercup (Ranunculus acris 'Flore Pleno') is a perennial herb that flowers April to June and reaches about 1.0 m, suited to full sun and moist soils.

https://en.wikipedia.org/wiki/Ranunculus_acris

Ranunculus acris 'Flore Pleno'

Buttercup | Ranunculus acris 'Flore Pleno'

Ranunculus acris 'Stevenii' is a perennial herb in the Ranunculaceae that typically reaches about 1.0 m and produces clear yellow flowers in spring. It favours open, sunny positions and tolerates a wide range of soil textures. Flowering occurs from April to June. The plant is toxic to humans and livestock if ingested, so position carefully.

Buttercup (Ranunculus acris 'Stevenii') is a perennial herb with yellow flowers from April to June that prefers full sun and moist, well-drained soils.

Ranunculus acris 'Stevenii'

Buttercup | Ranunculus acris 'Stevenii'

Ranunculus acris multiplex is a perennial in the Ranunculaceae that produces yellow spring flowers. Plants reach about 1.0 m in height and perform best in full sun. It grows in a wide range of soils from sandy to clay provided they remain moist or wet but not stagnant. Wear gloves when handling as the sap can irritate skin and the plant is harmful if eaten.

Meadow buttercup Ranunculus acris multiplex is a perennial with yellow flowers April to June, suited to full sun in moist, sandy to clay soils.

Ranunculus acris multiplex

Meadow buttercup | Ranunculus acris multiplex

Ranunculus bulbosus 'F. M. Burton' is a perennial buttercup in the Ranunculaceae that produces glossy yellow flowers from April to June. Plants reach about 0.3 m and are best sited in full sun. It will grow in sandy, loamy or clay soils provided they remain moist but well-drained. All parts are toxic, so avoid planting where children or animals might ingest foliage or flowers.

Bulbous Buttercup (Ranunculus bulbosus 'F. M. Burton') produces glossy yellow flowers from April to June and prefers full sun in moist, well-drained soils.

https://en.wikipedia.org/wiki/Ranunculus_bulbosus

Ranunculus bulbosus 'F. M. Burton'

Bulbous Buttercup | Ranunculus bulbosus 'F. M. Burton'

Ranunculus bulbosus 'Pleniflorus' is a perennial herb that flowers in spring, producing a concentrated display from April to June. It reaches about 0.3 m in height and prefers a sunny position. Plant it in soils that range from sandy to loamy or clay, kept moist but well drained. Do not allow grazing animals to eat the foliage fresh, as it is toxic to livestock if ingested.

Bulbous Buttercup 'Pleniflorus' is a European perennial flowering April to June, for full sun in moist but well‑drained sandy to clay soils; 0.3 m tall.

Ranunculus bulbosus 'Pleniflorus'

Bulbous Buttercup 'Pleniflorus' | Ranunculus bulbosus 'Pleniflorus'

Ranunculus lingua is a perennial herb in the Ranunculaceae that thrives in very wet, waterlogged ground. It is suited to pond margins and marshy spots where soils remain saturated. Flowering occurs from April to June. Handle with care: the plant is harmful if eaten and a skin irritant, so wear gloves when working with it.

Greater spearwort (Ranunculus lingua) is a water-tolerant perennial for pond margins and wet ground, flowering April to June.

https://en.wikipedia.org/wiki/Ranunculus_lingua

Ranunculus lingua

Greater spearwort | Ranunculus lingua

Ranunculus platanifolius ('Grandiflorus') is a perennial in the buttercup family that bears conspicuous white flowers. It prefers moist, well-drained soil in a sheltered position and will tolerate full sun to partial shade. The plant is native to Belgium, the Walloon Region and the Grand Duchy of Luxembourg. Flowering occurs from April to June.

Large white buttercup (Ranunculus platanifolius ('Grandiflorus')) blooms April to June and prefers moist, well-drained soil in full sun or partial shade.

https://en.wikipedia.org/wiki/Ranunculus_platanifolius

Ranunculus platanifolius ('Grandiflorus')

Large white buttercup | Ranunculus platanifolius ('Grandiflorus')

Ranunculus repens 'Flore Pleno' is a perennial buttercup that reaches about 0.3 m and flowers from April to June. It belongs to the Ranunculaceae and is native to Europe, Asia and northwestern Africa. The cultivar performs best in full sun on moist but well-drained sandy, loamy or clay soils and is fully hardy (H7). All parts are toxic to humans and animals if ingested, so avoid accidental feeding to children or pets.

Ranunculus repens 'Flore Pleno' is a fully hardy buttercup that flowers April to June and prefers full sun with moist, well-drained soils.

https://en.wikipedia.org/wiki/Ranunculus_repens

Ranunculus repens 'Flore Pleno'

Buttercup | Ranunculus repens 'Flore Pleno'

Ranunculus speciosus plenus of gardens is a member of the genus Ranunculus in the family Ranunculaceae and is sold under the common name Buttercup. It produces its main display in the UK from April to June. The name indicates a garden form associated with ornamental planting rather than a wild-recorded taxon. Expect it to be used for spring colour in cultivated beds and containers.

Buttercup (Ranunculus speciosus plenus of gardens) flowers in the UK from April to June and is used for spring displays.