Repeat Photography, Tumamoc Hill, 1958 (image) University of Arizona Caption This photograph was taken in 1958 by stake 912 in a flat area in the western part of the Desert Laboratory grounds on Tumamoc Hill in Tucson, Ariz. The plot's dominant shrubs are creosote bush (Larrea tridentate) and white ratany (Krameria grayi) plus some triangle-leaf bursage (Ambrosia deltoidea) and species of cholla cactus. Credit Photo credit: Raymond M. Turner, US Geological Survey. Usage Restrictions This photo may be used only to illustrate a story about the research described in the release, Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.