Heydon, Paul A., Grow Wild Native Plant Nursery and Biological Consulting, 3784 Highway 7, Omemee, Ontario K0L 2W0, Canada

• The Canadian Field-Naturalist Vol. 125 No. 3 (2011) - Notes
  Hairy St. John’s-wort (Hypericum hirsutum L.) in the Toronto Area, New to North America
  Abstract  PDF