Cotyledon rusbyi Greene, Bull. Torrey Bot. Club 10: 125. 1883; Echeveria rusbyi (Greene) A. Nelson & J. F. Macbride; Graptopetalum orpetii E. Walther

Stems with ascending, slender branches, 3-10 mm thick. Leaves: rosettes densely ces-pitose, 10-50-leaved, 2-6(-10) cm diam.; blade green or reddish, rhombic-obovate to oblanceolate, 1.5-5 × 0.8-1.8 cm, rough (especially on margins and keel with peglike or subclavate papillae 0.05-0.1 mm and often narrower), apex with slender apiculum 1-3 mm, surfaces not glaucous. Inflorescences mostly flat cymes; floral stems 0.4-1.8 dm; proximal leaves 2-18 mm; branches mostly 2-5, circinate or not, 1-12-flowered. Pedicels mostly 3-8 mm. Flowers (5-)6-7(-8)-merous; corolla 14-21 mm diam., tube [0.7-]2-3.5 mm, lobes 7-10.5 × 1.2-2.5 mm; pistils not hollowed near base, gradually narrowed to styles 1-1.5 mm. 2n = 62, 63, 64, 66, ca. 93, 124.

Flowering late spring. Rock crevices especially on north slopes and on shaded cliffs (at least at lower elevations); [0-]600-1700 m; Ariz.; Mexico (Chihuahua, Sinaloa, Sonora).

Southward in Mexico, the corolla tube in Graptopetalum rusbyi tends to be shorter. The Mexican plants have been confused with G. occidentale Rose of Sinaloa (R. V. Moran 1984).

SELECTED REFERENCE Moran, R. V. 1984. Graptopetalum rusbyi (Greene) Rose and G. occidentale Rose. Cact. Succ. J. (Los Angeles) 56: 169-176.