Tucson Pollen Today and Tomorrow - April

Weeks 1 & 2:   Cercidium spp (Palo Verde) are beginning to  produce yellow flowers that liberate pollen that has mild to moderate allergenicity.   More important sources of allergenic pollen at this time are Ambrosia deltoidea (triangle leaf bursage, rabbit bush),  Ambrosia ambrosiodes (canyon ragweed) and, later in the month,  Mulberry trees.  The Ambrosia plants are flowering vigorously this year and will cause another bad spring hay fever season.  Bermuda grass is starting to release pollen.    Olive trees will flower in the next 2 weeks.   Mesquite will bloom shortly.
The yellow flowers of  Acacia species are only weakly allergenic.   Other yellow flowers that will soon be highly visible and will produce some airborne pollen are displayed by plants of unknown allergenicity.  These include Larrea tridentata (Creosote Bush), and members of the Compositae family such as Encelia farinosa (brittle-bush) and Baileya multiradiata (desert baileya, desert marigold). 
 

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 4-1-2009