Anthriscus sylvestris ‘Ravenswing’ Cow Parsley. Esteemed for its dark coloring, Cow Parsley offers a layered 18 in. mound of luscious, plum colored, fernlike foliage. In early summer, branched stems produce airy umbels defined by small white flowers and pink bracts. Keep the blooms trimmed back to ensure an attractive habit.3' x 18"–2' July.