Tucson Pollen Today and Tomorrow - May

Weeks 1 & 2:  Cercidium spp (Palo Verde tree) is in full bloom, and most varieties of Mesquite trees are flowering now. Yellow flowers that are visible now include Encelia farinosa (brittle-bush) and Baileya multiradiata (desert baileya, desert marigold).  These flowers in the Compositae family produce some airborne pollen, but their allergenicity is unknown.   Other flowers out now are much less visible, but highly allergenic: Ambrosia deltoidea (triangle leaf bursage, rabbit bush) and Ambrosia ambrosiodes (canyon ragweed).    Bermuda grass has been flowering for at least 2 months.  Olive trees will flower shortly.  Male Mulberry trees and Arizona Ash are still producing pollen.

Note:  This information is based on ongoing observation of flowering allergenic plants in the Tucson metropolitan area, and not on pollen counts.   Appearance and persistence of any particular airborne pollen species in the air usually lags behind the onset of flowering of the plant of origin.                                                                        Back

Disclaimer:   This site is for educational purposes only.  Any information that you have found in this web site is not intended to replace medical care or advice given to you by your own physicians. You should consider consulting your local medical library and other web sites for additional information. 

Comments and suggestions welcome!   Email: schumach@u.arizona.edu
Content Owner:  Michael J. Schumacher, MB, FRACP, The University of Arizona
Updated 5-3-2009