ambrosia genus --- Aster subfamily 4

flatspine bur ragweed (Ambrosia acanthicarpa) -- in March -- Iron County, southern Utah       green & brown

western ragweed (Ambrosia psilostachya) -- in July -- Bellvue, Larimer County, CO

western ragweed (Ambrosia psilostachya) -- in July -- Mill Creek Link Trail, Lory State Park, CO   green & brown    

western ragweed (Ambrosia psilostachya) -- in August -- Orchard Cove Trail, Lory State Park, CO    green & brown

western ragweed (Ambrosia psilostachya) -- in August -- Bobolink Trail, Boulder County, CO

burrobrush (Ambrosia salsola var. salsola) -- in March -- I-15 in  southern Utah      white & cream  

skeletonleaf bur ragweed (Ambrosia tomentosa) -- in September -- Fossil Creek Reservoir, Fort Collins NA, CO     green & brown

skeletonleaf bur ragweed (Ambrosia tomentosa) -- in September -- Orchard Cove Trail, Lory State Park, CO

great ragweed (Ambrosia trifida) -- in August -- Well Gulch Nature Trail, Lory State Park    green & brown  

great ragweed (Ambrosia trifida) -- in September -- Well Gulch Nature Trail, Lory State Park, CO