The plant puts its blossoms (very small, five-petalled, white flowers) out in large flat clusters (umbels), looking, as its name suggests, like lace. The leaves and stem are hairy. The plant can stand two to three feet tall. The old umbels curl up and will form a cuplike "birds nest". A successful invader from the old world, by mid summer it can turn fields white with its lacy blooms. It is considered poisonous.