Ranunculus is a large genus of about -5,000 species of plants in the Ranunculaceae. It includes the buttercups, spearworts, water crowfoots and the lesser celandine (but not the greater celandine of the poppy family Papaveraceae).
They are mostly herbaceous perennials with bright yellow or white flowers (if white, still with a yellow centre); some are annuals or biennials. A few have orange or red flowers and occasionally, as in R. auricomus, petals may be absent. The petals are often highly luster, especially in yellow species. Buttercups usually flower in April or May 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 although for some species, such as R. aquatilis, a third, intermediate leaf form 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" — iceyéeyenm sílu in Nez Perce and spilyaynmí áčaš in Sahaptin. 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.
and many more