Ranunculaceae, the Buttercup family, is a large family, globally, it consists of around 1,800 species in about 50 genera. The family occurs throughout the world, but is most abundant in temperate and cool regions of the northern and southern hemispheres. Ranunculus is Latin for "a little frog", the name applied by Pliny the Elder (23-79 A.D.) to a group of plants in this family that grows where frogs abound. It's not an economically important family. The commercially available species are almost all ornamentals. Some genera are important as poisonous plants. The poisonous properties of Aconitum and Delphinium are well known, particularly to those in involved with cattle. Many, possibly most, other genera contain poisonous species. The compounds involved vary but include alkaloids (in Aconitum and Delphinium), protoanemonin (in Anemone, Clematis, and Ranunculus), and cardiac glycosides (in Helleborus). A drink of Aconitum tea was the lethal drug used for giving the death penalty in ancient times. Almost all members of the Ranunculaceae are herbaceous, but most species of Clematis are woody vines. The leaves are usually basal or alternate, but are opposite in Clematis. The leaves are usually without stipules, but stipules are present in Thalictrum, Caltha, and Ranunculus. The flowers are usually radially symmetric and bisexual, but Delphinium and Aconitum are bilaterally symmetric and Thalictrum has unisexual flowers. When both sepals and petals are present, there are usually 5, but sometimes 4, and sometimes no petals, but brightly colored sepals. The petals may have spurs that run between the sepals (as with columbines), or only some petals with spurs that run into the sepals (as in delphiniums). The flowers have numerous stamens, and either many pistils that develop into single-seed fruit or a few separate pistils that develop into many-seeded fruits. Fruits are either pods (follicles), seed-like (achenes), or berries.
Guide to Identify Presented Species of the Buttercup Family
FLOWERS WITH 5 YELLOW OR WHITE PETALS
Ranunculus – Buttercup Herbs of various height, erect or creeping, on dry to wet ground or in water.
Flowers yellow with mostly 5 showy petals and 5 smaller sepals.
Leaves basal and alternate, simple or divided into narrow segments.
FLOWERS WITH 5 PETALS AND 5 SPURS
Aquilegia – Columbine Plants usually 20-70 cm tall, freely branched. Open sites, foothills to alpine.
Flowers showy, nodding. Sepals 5, spreading. Petals 5, with slender spurs.
Leaves mainly basal, divided in 3's, long-stalked. Leaflets mostly round.
FLOWERS WITH SHOWY PETAL-LIKE SEPALS, VARIOUS COLORS
Anemone – Anemone Slender plants of various height. Mostly on dry sites, all elevations.
Flowers white, showy, 1-3 on long stalks, with 5 large, petal-looking sepals.
Basal leaves long-stalked, palmately divided into sections. Few stem leaves.
Caltha leptosepala – Mountain Marsh Marigold Low, alpine plant with fleshy, leafless stems, 5-10 cm tall. Wet, open sites.
Flowers white, solitary, 2-4 cm wide with 5-15 petal-looking sepals.
Leaves basal, oblong to heart-shaped, thick, waxy, long-stalked, wavy edges.
Clematis – Clematis Mostly woody vines, up to 5 m high. Open to shaded sites, moist to dry.
Flowers blue or white with 4 or more sepals, usually spreading.
Leaves opposite, compound, with stalked, lance-shaped leaflets.
Pulsatilla – Pasque Flower Silky-hairy plants. Moist to dry, open sites, montane-subalpine.
Flowers solitary with white or blue sepals, usually 6. Stamens bright yellow.
Basal and stem leaves long-stalked, finely divided in 3's.
Trollius laxus – Globe Flower Hairless herb, 10-40 cm tall. Moist to wet, open sites, montane-alpine.
Flowers white-creamy, 2-4 cm wide, solitary, with 5-9 petal-looking sepals.
Leaves palmately divided into 5 toothed segments, membranous lobes at base.
OTHER FLOWERS WITH NO OR VERY SMALL PETALS
Thalictrum – Meadow Rue Mono- or bisexual plants, branching. Usually at moist sites, foothills-montane.
Flowers greenish or whitish, in branches. Numerous stamens hanging down.
Leaves alternate, thin, repeatedly divided in 3's. The leaflets rounded.
FLOWERS IRREGULAR, MOSTLY BLUE. PLANTS VERY POISONOUS
Delphinium – Larkspur Poisonous plants, with several blue flowers in tall, narrow clusters.
Flowers have 2 pairs of small petals and 5 large sepals, 1 extending to a spur.
Leaves are basal and alternate, palmately cut into several narrow leaflets.
FLOWERS WHITE, WITH NARROW OR INCONSPICUOUS PETALS
Actaea rubra – Baneberry Branched plant, leafy, growing several red, glossy berries in the fall.
Flowers small, white, with slender petals, in dense, rounded clusters.
Leaves alternate, few, 2-3 times divided in 3's. Segments toothed and lobed.
Clematis ligusticifolia – Western White Clematis Woody vine, stems 3-6 m high, often in dense, tangled mats. Dry areas.
Flowers white-cream-colored, 2 cm wide, with 4 sepals and many flat stamens.
Leaves opposite, pinnately divided into 5-7 stalked, lance-shaped leaflets.
Alphabetical listing with links to presented species of the Buttercup family:
