Bloody dock, also known as bloody sorrel, is a perennial green in the rhubarb/buckwheat family (Polygonaceae). It is grown as both an edible and ornamental plant. It forms a small clump of beautiful green leaves with vivid red veins. The plant contains high levels of oxalic acid, which gives it a lemony flavor but means that it should only be enjoyed in moderation (as too much oxalic acid inhibits the body's ability to absorb some important nutrients like calcium). The leaves taste best when young and tender, getting tougher and somewhat bitter with age. In cold winters it dies back to its roots, but in mild winters might produce a few small leaves all winter. Performs best in zones 6 through 8.