Skip the Navigation

Air Regions
  Map of the DEP Regions
    Region 1 | Region 2
    Region 3 | Region 4
    Region 5 | Region 6

Air Topics
   Advisory Groups

  BulletAir Quality Home
  BulletSite Index
  BulletLatest News
  BulletUpcoming Events
  BulletContact Air Quality
  BulletAir Related Links

Bureau of Air Quality

Ragweed Pollen

How to Identify the Ragweed Plant

Ragweed Form Ragweed Leaf Ragweed Flowers Ragweed Stem
Form Leaf Flowers Stem

Common Ragweed

Scientific Name: Ambrosia artemisiifolia
Height: 1 to 5 feet
Stems: green, hairy
Leaves: divided into narrow segments, each irregularly lobed.
Flowers: 2 to 4 inch long terminal spikes of green to yellow flowers.

Interesting Notes

  • There are 17 species of ragweed in North America.
  • Ambrosia is the generic name of ragweed and in the Latin means "food of the gods."
  • Ragweed grows the best in sunny, newly-disturbed soils, free from competition with other weeds and grasses. It is often found along roadsides, vacant lots, river banks, and abandoned fields.
  • Ragweed starts blooming in Pennsylvania in mid-August as the days become shorter and the nights longer. Pollen production ends mid-September as temperatures start dropping below 60 °F.
  • It is estimated that one ragweed plant can produce up to 1 billion pollen grains.

BulletRagweed Pollen
BulletMonitoring Info
BulletAir Quality Home