Chelidonium majus
Poppy Family or Papavaraceae
  Pathology Images Inc. 2002 to  2004
A 1 to 2 foot tall plant with a slender, hairy stem and a yellowish-orange sap. Flowers, to inch wide with prominent stamens, are bright yellow, 4-petalled and borne in a loose terminal cluster. Leaves are alternate and divided into several intricately lobed leaflets. 
(Photographed at Sharbot Lake - July 1, 2004)