Locality: Seven Springs, Tonto National Forest (33.962300, -111.849000)

Abstract: The Seven Springs Region lies in the northwestern region of Tonto National Forest in Maricopa County, about 72 km northeast of Phoenix, Arizona. The study site covers about 39 km2 and includes Seven Springs Recreation Area, the southern and western sides of Humboldt Mountain, and portions of Cave Creek and Camp Creek. The site?s elevations range from 1100 to 1600 m and include areas of Sonoran desertscrub, interior chaparral, semidesert grassland, and riparian vegetation. A floristic inventory was conducted in the study area from 1999-2002 with the primary objectives of cataloguing the vascular plant flora and identifying the presence of sensitive, threatened and endangered species of plants in the region. After nearly three years of plant collections and thorough herbarium searches at Arizona State University and Desert Botanical Garden, 444 taxa including 438 species and 6 infraspecific taxa were documented. The best represented families include, in descending order, Asteraceae, Poaceae, Fabaceae, and Scrophulariaceae. The most diverse genera include Chamaesyce (with 7 species) and Bouteloua, Eragrostis, Eriogonum, Juncus, and Muhlenbergia (each with 5 species). Plants not native to the United States account for 54 species (12.2% of flora), and 45 species are obligate or facultative wetland plants (10.2% of flora). No sensitive, threatened, or endangered species were found. Comparisons to other floristic studies in the region revealed the highest similarity to Superstition Mountains Wilderness Area and the Sierra Ancha Wilderness Area, both of which have a high percentage of elevational overlap with the Seven Springs Region