Seasonal Allergies


Types of Pollens

Tree Pollens and Allergies

Not every kind of tree produces pollen that causes nasal allergies. But enough do to make seasonal allergies from tree pollens a major health issue.

Common Allergy-Producing Trees

  • alder
  • ash
  • beech
  • birch
  • box elder
  • cedar
  • cottonwood
  • cypress
  • elm
  • eucalyptus
  • hickories
  • juniper
  • maples
  • mesquite
  • mulberry (nonfruiting)
  • oak
  • olive
  • orange
  • osage
  • pecan
  • palm
  • poplar
  • sweet gum
  • sycamore
  • walnut
  • willow

Grass Pollens and Allergies

Grass pollen is a common allergen. Yet of the more than 1,000 types of grass that grow in North America, only a few produce pollens that trigger nasal allergies.

Common Allergy-Producing Grasses

  • Bermuda
  • blue (especially Kentucky)
  • brome
  • canary
  • johnson
  • orchard
  • redtop
  • rye
  • salt
  • Sudan
  • sugar beet
  • sweet vernal
  • timothy
  • wild oats

Weed Pollen and Allergies

Weeds are the largest source of allergy-triggering pollens in North America. In late summer and early fall in North America, ragweed pollen is the number one cause of hay fever. A single ragweed plant can produce millions of grains of allergy-producing pollen.

Common Allergy-Producing Weeds

  • cockleweed
  • goosefoot
  • hemps
  • mash elder
  • nettle
  • pigweeds
  • plantain
  • ragweed
  • Russian thistle (tumbleweed)
  • sages (mugworts)
  • sagebrush
  • sheep sorrel
  • smotherweed

For more information about allergies and pollens, see the next page.

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