Six genus and about 150 different species belong to this Family. Among them, the most important allergologically are Birch tree (Betula alba or pendula), Alder (Alnus glutinosa), and Hazel (Corylus avellana).
They are trees and bushes mainly located in the north and center of Spain and Europe, where they have greater allergologic relevance (see maps).

Birch tree pollen is spheroidal, with small-medium size (20-25 µm in diameter), with a somewhat granulated surface, and it has three pores. Its flowering season is between March and May.

 

Birch *
 

Hazle pollen is triangular, small (20-26 µm in diameter), with a somewhat granulated surface, and three pores. Its flowering season is between January and March.

   
   

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Birch **
Birch **
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Birch *

Birch *

 

   
   
   
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Optical microscope
pollen view
**
Electronic microscope
pollen view
**


* Photos (c) Laboratorios LETI, S.L.
** Photos (c) Menarini, S.A. - Hospital Clínico de Barcelona

 

(c) 2002 Paediatric Allergy Unit, LA FE HOSPITAL
VALENCIA
SPAIN
webmaster@alergiainfantillafe.org

 

Pollen and allergy: Introduction | Pollen counts |
The most allergenic pollens: Grasses | Urticaceae | Compositaceae | Chenopodiaceae/Amarantaceae | Plantaginaceae | Euforbiaceae | Oleaceae | Betulaceae | Cupresaceae | Platanaceae | Fagaceae
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