Cow parsley (Anthriscus sylvestris) is a European native biennial or short-lived perennial in the carrot family (Apiaceae), naturalized across much of North America. It produces tall hollow stems topped with flat white umbels in mid-spring along roadsides, hedgerows, and woodland margins. The cultivar 'Ravenswing' is widely grown as a garden ornamental for its deeply cut, near-black foliage and is the primary reason gardeners plant this species intentionally.
Plants form a basal rosette in year one, then bolt to 3–5 ft in year two, set seed prolifically, and die. Self-seeding is aggressive on disturbed, fertile ground. Dangerously easy to confuse with poison hemlock (Conium maculatum): always check stems before handling any unidentified Apiaceae — hemlock stems are glabrous with purple blotches, while cow parsley stems are distinctly hairy and unspotted. Prefers moist, fertile soil and tolerates considerable shade. A neutral to slightly alkaline pH suits it well.
The roots contain deoxypodophyllotoxin and podophyllotoxin, compounds with documented antitumor and antiviral activity used as pharmaceutical precursors. Young spring leaves have a mild flavour and have been used as a parsley substitute in European traditional cooking. Plants provide early-season nectar and pollen to hoverflies and other pollinators before many other umbellifers come into season.