1. A large biennial herb native to Eurasia and Africa, naturalized in North America, having fernlike leaves and white flowers; all parts extremely poisonous
   "The botanist warned students to avoid touching the poison winter fern";
   - hemlock, poison hemlock, poison parsley, Nebraska fern, Conium maculatum

Derived forms: winter ferns

Type of: poisonous plant

Part of: Conium, genus Conium