Materials are included The UA campus has long been the repository of unique trees imported for research or landscape interest. The olives were planted in 1885 as variety trials - giving the citizens of the Arizona Territory options for new crops. The early-20th century Sonoran Desert explorers worked from the University of Arizona. Their plant collecting trips helped to green" the campus. After WWII, the growing population of Tucson enjoyed the cool shade and the lush lawns. More recently, hundreds of xeric trees from urban sites in arid lands around the world were tested on the campus--to determine their suitability for landscape plants in the desert southwest. Today's campus represents UA heritage, botanical research, faculty and student travel historic landscape styles, and recent sensitivity to water use.