Perennial ragweeds (Ambrosia) in Michigan, with the description of a new, intermediate taxon
Wagner, Warren H. (Warren Herbert), 1920-2000 Beals, T. F.
Article
1958
Rhodora
60
177--204
BioStor
[Cambridge, Mass., etc.] New England Botanical Club [etc.]
BioStor: https://biostor.org/reference/139206