any tall coarse umbelliferous plant of the genus Heracleum, such as H. sphondylium of Europe and Asia, having thick stems and flattened clusters of white or purple flowers
Also called: hogweed, keck
cow parsnip in American English
any of several perennial plants (genus Heracleum) of the umbel family, with flattened clusters of white or purple flowers and thick, tubular stems