Get aeroallergen readings for Birch.

Important genera:

Birch (Betula) and Alder (Alnus)

Tree pollen is dominant in the spring.
Birch pollen season extends from February to May.
Alder pollen season extends from January to April.

Birch and Alder trees in Missouri:

• White or Weeping Birch (Betula alba, B. pendula, B. verrucosa)
• River or Red Birch (Betula nigra)
• Hazel or Common Alder (Alnus serrulata)
• Smooth or Tag Alder (Alnus rugosa)

Facts about Birch and Alder

• The Betulaceae family consists of six genera which are found in the Northern Hemisphere, five of these are native to North America.
• Most birches have very scaly bark.
• Seven alder species are native to North America, all of which are pollinated by wind and shed copious amounts of pollen.

Birch and Alder Allergenicity

• Alder pollen can be found miles away from any source due to the abundance of pollen produced, their small size, and light weight. Many people have allergic reactions to this pollen.
• Common alder flowers from March to April.
• Smooth or Tag alder is among the first spring flowers, blooming in January and February in some regions.
• River or Red birch shed large quantities of pollen and constitute one of the important tree pollens in causing hay fever. It flowers from April to May.