Alder (Alnus)
Alder Genus Details
Alders are deciduous trees or large shrubs that often grow together in moist soils in wooded areas of North America. All species have separate drooping male and upright female flowers on catkins of the same plant. Flowering precedes the opening of leaf buds and usually occurs during January to April depending on latitude and elevation.
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European Alder (Alnus glutinosa).
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Speckled Alder (Alnus incana).
Alder Allergy Info
All species have windborne pollen which has been reported to be a significant allergenic cause. People sensitive to one alder species are usually sensitive to all species.
Alder Pollen Description
Pollen grains of Alnus are oblate to oblate-spheroidal and usually 4-5 porate. Their exinous thickened bands that extend in pairs from aperture to aperture distinguish the grains.
Pollen grains vary in size from 19-21 x 23-30 micrometers.
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Alnus rugosa, single grain
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Alnus rugosa, multiple grains
Species in This Genus
Allergenicity Legend:
Mild Allergen |
Moderate Allergen |
Severe Allergen |
Allergy Test Available
Mild Allergen |
Moderate Allergen |
Severe Allergen |
Allergy Test Available
Alder (Alnus) is a genus of the BETULACEAE family.
This genus includes the following allergenic species:
This genus includes the following allergenic species:
