The goals of this photo site are to have photographs of all plants found in SPRNCA, to provide a guide for identifying the plants, to show the beauty of the wildflowers found in SPRNCA, and to show wildflowers currently in bloom and provide directions to where they are in flower. The SPRNCA plant site was started August 26, 2007 and is under construction.
Three useful references for identifying plants of SPRNCA are:
Epple, A. O. A Field guide to the plants of Arizona. 1995. The Globe Pequot Press, Guilford, Connecticut. 347 p. $24.95. The introduction to this guide notes that Arizona has 3000 species of plants and that 850 of them are pictured in the book. It does not include grasses and most weeds. The photographs of trees are arranged according to leaf shape while those of cacti are arranged according to the overall shape of the plant. The arrangement of photographs of plants according to the color of their flowers facilitates identifying species. The guide treats most but not all of the species occurring in SPRNCA.
Makings, E. 2006. Flora of the San Pedro riparian national conservation area. Desert plants, 22 (2). 104 p. $10. This publication is primarily intended for professional botanists but is of considerable use to amateurs also. It provides descriptions and photographs of major plant associations and has 20 pages of color photographs of plants. It includes several species not treated in Epple. A major shortcoming is the absence of an index.
The Internet. A wide variety of online guides assist in the identification of plants. Perhaps the most authoritative is that of the United States Department of Agriculture http://plants.usda.gov/