Allergy-causing WeedsPigweed (Amaranthus sp.)
Ragweed (Ambrosia sp.)
Sagebrush (Artemisia ludoviciana)
Mugwort (Artemisia vulgaris)
Lamb's quarters (Chenopodium album)
Summer cypress (Kochia scoparia)
Alfalfa (Medicago sativa)
Plantain (Plantago sp.)
Sorrel (Rumex sp.)
Tumbleweed, Russian thistle (Salsola kali, also S. tragus, S. iberica, S. australis)
Nettle (Urtica sp.)
Cocklebur (Xanthium strumarium)
(Looking to plant a low-allergy garden? Learn more about "sneeze-free" plants and low-pollen houseplants.)
All images courtesy of the American Academy of Allergy, Asthma and Immunology, unless otherwise indicated.