PLANT: Shrub, erect, 0.5-2 m tall. STEMS: with somewhat slender, spreading, lateral branches. Thorns up to 6 cm long. LEAVES: with decurrent whitish petioles less than 2 mm long; blades narrowly oblanceolate to linear, 3-10 mm long, 1-3 mm wide, villous to glabrous, light green; apices mucronate; bases tapering. INFLORESCENCE: of 1-4 flowers; pedicels 4-7 mm long. NOTES: Open slopes and washes: extreme se AZ in the vicinity of Guadalupe Canyon, Cochise Co.; 1200-1500 m (4000-5000 ft.); flowering late spring and summer; s NM, s TX, and n Mex. Adolphia infesta has an extremely narrow distribution in AZ. This description is based upon a single collection (R.M. Turner & J.B. Turner 89-1, ARIZ 285077, ASU 172509) from near the AZ-NM state border. Another specimen from NM, (W.J. Hess 2432, housed at MOR), has been collected in Guadalupe Canyon on the w side of the Peloncillo Mountains. Additional searches for A. infesta should be conducted throughout the area. REFERENCES: Kyle Christie, Michael Currie, Laura Smith Davis, Mar-Elise Hill, Suzanne Neal, and Tina Ayers, 2006 Vascular Plants of Arizona: Rhamnaceae. CANOTIA 2(1): 23-46.