still with a yellow centre); some are annuals or biennials. A few species have orange or red flowers. There are usually five petals, but sometimes six, numerous, or none, as in R. auricomus. The petals are often highly lustrous, especially in yellow species. Buttercups usually flower in the spring, but flowers may be found throughout the summer, especially where the plants are growing as opportunistic colonisers, as in the case of garden weeds.
The Water crowfoots (Ranunculus subgenus Batrachium), which grow in still or running water, are sometimes treated in a separate genus Batrachium. They have two different leaf types, thread-like leaves underwater and broader floating leaves. In some species, such as R. aquatilis, a third, intermediate leaf type occurs.
Ranunculus species are used as food plants by the larvae of some Lepidoptera species including Hebrew Character and Small Angle Shades. Some species are popular ornamental flowers in horticulture, with many cultivars selected for large and brightly coloured flowers.
In the interior of the Pacific Northwest of the United States the buttercup is called "Coyote’s eyes". In the legend Coyote was tossing his eyes up in the air and catching them again when Eagle snatched them. Unable to see, Coyote made eyes from the buttercup.