This photo, taken in 1978 by stake 912 in a flat area in the western part of the Desert Laboratory grounds on Tumamoc Hill in Tucson, Ariz., shows the changes since 1958. The same species are dominant. All the species had increased their cover inside the plot. A new species, whitestem paperflower (Psilostrophe cooperi) had appeared in the plot. Good growing conditions in 1978, including good rains, fueled the increase in ground cover by both annuals and seedlings of perennial plants.