Common ButtercupRanunculus acris
From the link ☼
Hairy perennial, often reaching 3 feet in height, with stems much branched above. Lower leaves deeply 3- to 5-lobed, the lobs also deeply cut, upper leaves reduced and consisting of 3 to 4 narrow segments. Flowers yellow, 1 inch or more in diameter.
Spiny-fruited buttercup (R. muricatus L.) Is annual, 1/6 to 1 foot tall. Leafy branching stems single or clustered. Leaves petioled, blades 3-to 5-lobed, toothed. Fruit 1/4 inch or slightly longer with smooth border, stout curved beak, and generally spiny faces.
These species were introduced from Europe. Roughseed buttercup is common in the western United States, but tall buttercup is now well established throughout most of North America. Butter cup species usually occur in meadows and pastures and are generally avoided by livestock. Like other species of Ranunculus, tall buttercup has been reported to cause livestock poisonings.
