The common buttercup species, Ranunculus--known for sunny yellow, shiny petaled blooms that carpet forests and meadows in spring--is a childhood favorite for many gardeners. Its close cousin, the flowering Persian buttercup, is a pumped-up variety of the wildflower beloved for cut arrangements.
Creeping and meadow buttercup are best known for their glossy, buttery colored petals in sets of five surrounded by fringed, deep green foliage. Double varieties with more petal sets have been cultivated. However, the most common wild species are identified by small, bright yellow blooms that like to grow under trees in forests, meadows, or even along roadsides where other plants won't grow.
Ranunculus asiaticus is recognizable by petals densely packed in rows surrounding an inset, deep green or purplish center. Blooms range in color from white to red, pink, yellow and orange with lacy foliage.
Best for mass planting or as ground cover, meadow buttercup (R. acris) will grow well in just about any soil conditions, with full sun and proper moisture. The variety "Flore Pleno" has double blooms, while Buttered Popcorn (R. Repens), a taller buttercup species, has attractive silver-green foliage. The Persian buttercup makes a lovely addition to Victorian or English-style gardens. Grow them in perennial beds or with other tuber or bulb flowering plants as an early spring pop of color and texture.
Ranunculus repens and acris are both wildflower or weed varieties in the buttercup family. The blooms are quite small, typically measuring less than 1 inch across. Plants of these species can grow horizontally or as tall as 2 feet. The Persian buttercup, R. asiaticus, bears larger, bulb-borne blooms that can flower 2 inches across.
Ranunculaceae is a family of diverse flowering structures that flourish in many climates. The wild flower species, R. acris and R. repens grow in most parts of the United States. Prolific in the East and West Coast states and most of the north, there have also been wild spottings in many southern states. Ranunculus asiaticus is a popular perennial bulb that is hardy in USDA climate zones 8 to 10, and will grow in warm spring and early summer conditions.
R. repens, the creeping buttercup, is considered a noxious weed in several states and cannot be planted by the home gardener. Be aware of potential prohibitions in your area before planting.