For a useful index to desert plants of our area, see this link to a page by Brad Fiero of Pima Community College: Desert Ecology
Please note that our treatments of these subjects are inescapably limited and cursory. For those seeking more detailed treatment of life forms we explore, see the University of Arizona's website, The Tree of Life; and the UC Berkeley Taxon Lift. For systematic classifications, UC Berkeley's Green Plant Phylogeny Research Coordination Group provides two amazingly detailed sites, which can be accessed at Hyperbolic Trees. This site enables viewers to consult either a "Research Tree" (providing a highly detailed series of tree diagrams) or a "Teaching Tree" (which will eventually provide pictures, texts, and links to other sources, though less detailed trees of plant types). For a more general exploration of the UCB botanical resources, see UCB Herbaria. U. Vermont Plants also provides limited systematics information.