Ecology:

The Ashy Dogweed is primarily found in the area known as South Texas Plains or the Cenzia-Blackbrush-Creoste Bush Brush. This area was thought to have been originally Grasslands. The only known counties in Texas, where this perennial herb exists, are Zapata and Webb Counties. The Ashy Dogweed used to occur in Starr County, but has no longer been found there since 1932.

The ashy Dogweed grows in:

• open areas of fine sandy loam.
• Maveric-Catarina soil.
• soils that are clayey, saline, deep to shallow, fine textured, and slowly permeable.
• Eocene sandstone and clays.
• elevations of ~ 400 to 415 feet.
• climates that are hot (temperature averages of ~ 73 degrees F annually), semi arid, and suffer from droughts (average annual precipitation of ~ 20 inches with peaks in September and May to June).