Allergy Information

The chenopods are a particularly allergenic plant group; a likely cause of allergy.

Genus Details

The term chenopods is used to represent members of the Chenopodiaceae and Amaranthaceae families. The pollen grains of these two families are so similar that they are impossible to differentiate between species, even by trained technicians, so they are listed collectively as "chenopods". Some of the plants found in these families include amaranth, pigweed, waterhemp, russian thistle, lamb's quarters, and kochia. These plants are found throughout the United States and flower typically in the summer and fall. The pollen of these families can be highly allergenic and is a cause of concern to allergic individuals.

Pollen Description

Pollen grains are spheroidal and have between 30-65 pores. The exine is thin and granular. The various species of Amaranthus are difficult to tell apart using a light microscope.

Grains are 18-31 micrometers in diameter.

Genus Distribution

The shaded areas on the map indicates where the genus has been observed in the United States.

- Native, observed in a county 

- Introduced, observed in a county 

- Rarely observed