Ambrosia psilostachya
Family:Composite or Sunflower (Compositae)
Size: Flowering stems at the tips are 2 - 5 in. long, containing many heads of male flowers. Female flowers are tiny and hidden in the leaf axils.
Date: 8/12/2001
Other names: Western ragweed, perennial ragweed.
Notes: 12 species of Ambrosia in Arizona.
This plant is found on the Appleton-Whittell Research Ranch Working Check list of flora.
Cuman Ragweed plant profile on the USDA Plants server.