TALL BUTTERCUP, Ranunculus acris L. 1, plant in bloom; 2, seed head; 3, seeds. Perennial, reproducing by seeds. Stems erect, branched above, hairy, 1 to 3-1/2 feet (30 to 106 cm) tall. Leaves alternate, hairy, palmately divided into narrow segments. Flowers usually bright yellow but sometimes cream-colored, with 5 to 7 petals. Seeds numerous, dark brown, about 1/8 inch (3 mm) long, minutely pitted, flattened, with hooked beak; formed in a rounded head. Found in pastures; does not persist in cultivated crops. This plant contains an acrid juice which is somewhat poisonous if eaten by livestock, often blistering the mouth and intestinal tract.