Allergies Home > What You Need to Know About Pollen and Hay Fever
The type of allergens in the pollen is the main factor that determines whether the pollen is likely to cause hay fever. For example, pine tree pollen is produced in large amounts by a common tree, which would make it a good candidate for causing a pollen allergy. It is, however, a relatively rare cause of pollen allergy, because the type of allergens in pine pollen appears to make it less allergenic.
Among North American plants, weeds are the most proli?c producers of allergenic pollen. Ragweed is the major culprit, but other important sources are:
- Redroot pigweed
- Lamb's quarters
- Russian thistle (tumbleweed)
- English plantain.
Grasses and trees, too, are important sources of allergenic pollens. Although more than 1,000 species of grass grow in North America, only a few produce highly allergenic pollen.
It is common to hear people say they are allergic to colorful or scented flowers, like roses. In fact, only florists, gardeners, and others who have prolonged, close contact with flowers are likely to be sensitive to pollen from these plants. Most people have little contact with the large, heavy, waxy pollen grains of such flowering plants, because this type of pollen is not carried by wind, but by insects such as butterflies and bees.
Some grasses that produce pollen include:
- Timothy grass
- Kentucky bluegrass
- Johnson grass
- Bermuda grass
- Redtop grass
- Orchard grass
- Sweet vernal grass.
Some trees that produce pollen include:
- Box elder
- Mountain cedar.