The tall or meadow buttercup is an erect, hairy, perennial plant two to three feet high. The basal leaves are long-stalked, three to seven parted, each division cleft into linear crowded lobes. The upper leaves have shorter stalks, and fewer lobes. The flowers are bright yellow, numerous, about an inch in diameter, with roundish petals two or three times the length of the pointed sepals. The fruit clusters are round, one-quarter to one-third inch broad. The seeds are flattened, with a short beak. The plant is in bloom from May to September. It was introduced from Europe, and is now common in fields and on roadsides across the American continent.
This species of buttercup is less harmful than the cursed crowfoot and, when dried with the hay, forms a large part of the fodder available in some districts, but it must be remembered that all the buttercups are of a poisonous character and under certain conditions and seasons are liable to become very injurious. Long states that "R. acris L., the acrid buttercup or tall crowfoot, is a frequent cause of poisoning in cattle," and Cornevin says "it is perhaps the species which causes the most accidents."
Our native small-flowered buttercup (R. aborlivus L.) which may be distinguished by its round heart-shaped root leaves and pale yellow flowers whose petals are shorter than the reflexed sepals, is equally capable of causing irritation and blistering, as is also the smaller spearwort (R. reptans L.). All other buttercups of the swamps and woods contain more or less acridity.