Reference:Howell1959a
Verbatim text: Howell, J. T. 1959. Distributional data on weedy thistles in western North America. Leafl. W. Bot. 9: 17–32.
Author: Howell, J.T.
Year: 1959
Title: Distributional data on weedy thistles in western North America
Journal: Leafl. W. Bot
Volume: 9
Pages: 17–32