Among the names of trees whose pollen are known to produce hay fever there are some that are commonly known such as the elm, oak, and maple, and others that are generally less popular such as the hackberry, poplar, and alder. Our city dwelling population in the United States is much more familiar with the commercial by-products of the hay fever trees rather than with the trees themselves. Many of us can recognize the oak church doors, the walnut dresser, the maple floor, or the ash staircase, that we encounter in our daily activities. But few can name these woods when they are still in their tree state. Nor is it important for the average individual to be able to do so. But, if you are allergic to the pollens of these trees, how are you going to avoid them if you can’t recognize them? To aid yourself in becoming familiar with these trees we recommend that you read This Green World by Rutherford Platt. In this book you will find exquisite color plates of many trees, grasses and flowers.
The list below represents the common names of trees whose pollens have been reported by one or another investigator as causing hay fever symptoms in persons living in the United States.
TABLE I
TREES RELATED TO HAY FEVER
Name Time of Pollination
Ailanthus June Alder March April May Ash April May June Aspen March April May Beech May Birch April May Elm March April Hackberry April May Hazel February March Hickory May June Linden May Locust May Maple March April Mesquite May June July Mountain Cedar December January February Mulberry May Oak April May June Olive April May Pecan April May Poplar April Privet May June Spruce December Sycamore April May Walnut May June Willow March April May June
In any analysis of trees related to hay fever it is difficult to list them in terms of their symptom-producing importance. A class of trees that is the predominant cause of spring hay fever symptoms in one locality may be non-existent in another area. For example, if you live in the southern part of Texas you may suffer from the effects of the mountain cedar which pollinates there from late December to February. In the United States this tree is found only in Texas and New Mexico. In California you may suffer from the pollens of the black walnut tree which is abundantly cultivated there. The thousands of cases re-ported in California as being effected by this tree, makes it an important factor for that state. Nevertheless, the black walnut is unimportant as a factor in hay fever in the East, where relatively few cases are noted. We can multiply examples of this kind many times over. Thus it is evident that an arbitrary listing in alphabetical order, as we have employed above, is definitely warranted.
Since this book is intended for persons interested in hay fever from a practical point of view, we shall consider only the trees whose pollen effects are widely recognized.