Ranunculus pallasii, commonly known as Pallas’ buttercup or the arctic buttercup, is an aquatic or semi-aquatic perennial herb in the family Ranunculaceae. It is native to the circumpolar arctic and subarctic regions, including the northern reaches of Russia, Alaska, Canada, and parts of Scandinavia, where it thrives in brackish marshes, tundra pools, and tidal flats. The genus name Ranunculus is Latin for "little frog," a reference to the many species in this genus that grow near water, while the species epithet pallasii honors the 18th-century German zoologist and botanist Peter Simon Pallas, who explored the natural history of Russia. Historically, the plant has served as an emergency or supplemental food source for indigenous Arctic peoples, such as the Inuit and Yup'ik, who possess the traditional knowledge required to process its inherent toxicity.

The plant is characterized by its creeping rhizomes and long-petioled, succulent leaves that are often deeply lobed into three segments. It produces solitary flowers with white or occasionally pale-pink petals, distinguishing it from the yellow-flowered buttercups more common in temperate zones. As a specialized extremophile, Ranunculus pallasii is ecologically vital for stabilizing northern wetlands and provides a seasonal food source for migratory waterfowl. Its growth habit is primarily prostrate, allowing it to withstand the harsh winds and freezing temperatures of the high tundra.

As a food source, Ranunculus pallasii is primarily utilized for its young shoots and succulent leaves. In traditional Yup'ik and Inuit practices, the plant is harvested in early spring before it flowers, at which point its chemical defenses are less concentrated. It is rarely, if ever, consumed raw in significant quantities; instead, it is typically boiled as a potherb or fermented in "sour docks" (a traditional greens preserve) alongside other tundra plants to mitigate its acridity and potential toxicity. In modern times, its usage has declined significantly, remaining largely a niche element of traditional ecological knowledge rather than a mainstream dietary staple.

Nutritionally, the plant provides a source of Vitamin C and minerals during the short Arctic growing season. However, like all members of the family Ranunculaceae, Ranunculus pallasii contains the bioactive compound ranunculin. When the plant tissues are crushed or chewed, ranunculin is enzymatically converted into protoanemonin, a volatile, yellowish oil that is a potent irritant. Protoanemonin can cause severe blistering of the skin and mucous membranes, and if ingested in large quantities, it may lead to gastrointestinal distress, dizziness, or more severe systemic poisoning. Thorough cooking or drying the plant usually causes the protoanemonin to dimerize into anemonin, which is significantly less toxic and non-irritating.