Definition of Pollen Pollen: Small, light, dry protein particles
from trees, grasses, flowers, and weeds that may be spread by
the wind. Pollen particles are usually the male sex cells of a
plant, and they are smaller than the tip of a pin. Pollen is a
potent stimulator of allergic responses. It lodges in the mucous
membranes that line the nose and in other parts of the
respiratory tract, causing irritation and histamine reactions.
Last Editorial Review: 3/19/2012 Back to MedTerms online medical
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