A 10 year survey of the hay fever plants and important atmospheric allergens in the San Antonio, Texas, metropolitan area

Abstract

1. 1. A botanical survey of the hay fever plants in the metropolitan area of San Antonio, Texas, is presented. 2. 2. Detailed data are given about the types, abundance, and seasonal occurrence of atmospheric pollens and fungus spores found during a 10 year period of study which was carried out from Jan. 1, 1951, through Dec. 31, 1960, in San Antonio, Texas. 3. 3. Pollens are present in the air over the entire year with the Quercus virginiana (live oak) and the Carya pecan (pecan) being present in large quantities in the spring. The Amaranthus species (careless weed) and grasses, Cynodon dactylon (Bermuda grass) and Sorghum halpense (Johnson grass), appear during most of the year but in largest quantities during the early summer. The Ambrosiae appear in the late summer and fall months. The Juniper sabinoides (mountain cedar) is a heavy pollen contributor during the winter, becoming most important particularly to those migrants who have never been exposed to this toxic pollen. Multiple fungus spores are found in the air during the entire year with spring and fall peaks, which add to the clinical symptoms caused by the pollens. 4. 4. A perennial allergy problem exists in the metropolitan area of San Antonio and is evidenced by the presence of large amounts of allergens and molds in the air throughout the year. The abundance of pollen varies greatly with the prevailing winds and their direction, and the amount of rainfall.