UA logo Allergy and Asthma in the
Southwestern United States
Information for patients with allergy and related problems
in the Southwest

Plants Known to Produce Allergenic Pollen in Southern Arizona  
Key to recognition of allergenic plants
(for pictures, click the links) 

Trees and shrubs     Grasses and weeds                   Return to menu

Common Name Latin Name Flowering months (Tucson) Comments
Ash, Arizona Fraxinus velutina  March-May Ornamental in Tucson
Cottonwood Populus Fremontii Jan-March Grows near  washes and streams
Cypress, Arizona Cupressus arizonica  Oct-April  Allergens similar to those in introduced species  e.g. Italian Cypress
(C. sempervirens)
Desert Broom Baccharis sarothroides Sept-Feb Grows in disturbed soil.  Seeds with cotton-like plumes fly in the wind
Elm, Chinese Ulmus parvifolia Feb-April Uncommon in Tucson
Hackberry Celtis pallida Spring,  fall  Widespread
Juniper  Juniperus Deppeana, monosperma Oct-April Distinctive berries.  Common at higher elevations.  Ornamental species of Juniper commonly planted are also allergenic
Mesquite  Prosopis juliflora March- August  Common tree in and near washes.  Has long beans, rough bark
Mulberry Morus alba, rubra Feb-March Male “fruitless” tree is allergenic
Oak Quercus  March-June Many species - Quercus Emoryi   Quercus Gambelii   Quercus turbinella   Quercus virginiana
Olive tree  Olea europaea March-May Low pollen varieties available
Palm trees:
Canary Island Date Palm

Phoenix canariensis
- Minor importance as allergens

Feather palm with massive trunk
Desert Fan Palm Washingtonia filifera Trunk partly or entirely covered with dependent dead fronds 
Mexican Fan Palm Washingtonia robusta Very tall, graceful fan palm with smooth trunk
Palo Verde Cercidium April-June Has smooth green trunk, tiny leaves, covered with yellow flowers in spring
Pecan Carya pecan Feb-April Orchards near Green Valley, AZ
Pepper Tree Schinus molle June-August Commonly planted ornamental tree
Privet Ligustrum lucidum April-June Tree or hedge 
Sumac, African Rhus lancea Jan-Feb Narrow leaves, clusters of small berries.  
Sycamore, Arizona Platanus Wrightii March-June Used in parks, streets. Very similar to P. racemosa, California sycamore
Tamarix, Salt Cedar Tamarix aphylla March-Sept Gray-green needle-like leaves
Walnut, Arizona Black Juglans major March-June Park and street ornamental tree, found with Cottonwood near streams

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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:
Content Owner:  Michael J. Schumacher, MB, FRACP, The University of Arizona