It’s an unusual name for a weed: Rabbit Bush. And although it is not clear where the name for this Arizona native variety of ragweed comes from, one thing is clear: there is a lot of it and it’s a major cause of allergy problems in the spring. In fact, Rabbit Bush is one of the most prevalent spring allergenic weeds in South Mountain Park and is therefore a significant source of ragweed pollen for Ahwatukee and surrounding areas. Rabbit Bush (technically Ambrosia (Franseria) deltoidea and also known as triangle bur ragweed or tirangleleaf bursage) comes to life in the spring, particularly if we have had winter rain, producing copious amounts of pollen in the Arizona Sonoran desert from March until May. Allergenically, it is closely related to other varieties of ragweed found throughout the Unities States and will trigger allergy symptoms in patients who have had problems with ragweed before moving to Phoenix. Other native varieties of ragweed found in the Sonoran Desert include Canyon Ragweed, fond of desert washes, and Desert Ragweed, a smaller but also prevalent ragweed in the Phoenix area.