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11 allergy-inducing pollen producers

By: Russell McLendon on April 21, 2011, 7:30 a.m.

Photo: Bob MacInnes [CC BY 2.0]/Flickr

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Ryegrass is often grown in lawns, but most of its pollen comes from pastures, wild areas and roadsides, since it usually has to be a foot tall to flower. Not to be confused with rye, a grain crop like wheat, ryegrass is one of the most potent and widespread of all grass allergens.

Habitat: Native to Europe, Asia and North Africa; cultivated worldwide

Description: Single-stemmed tuft grass

Allergenicity: Moderate to severe

Allergy season: June to August

Tips: If you have a ryegrass lawn, keep it mowed (or at least less than a foot tall). Beyond that, avoid unidentified grass pastures in summer, and consider staying indoors from 5 to 10 a.m. with the windows closed.