Graptopetalum rusbyi

Graptopetalum rusbyi has a limited U.S. range encompassing the Apachian Floristic area (Arizona to New Mexico), and occurs southward in Sonora and Sinaloa; it grows on steep canyon slopes and shaded cliffs.

G. rusbyi occurs in Arizona in Greenlee, Graham, Gila, Maricopa, Pinal and Pima counties (Kearney and Peebles 1960). One location has been recorded in the extreme southwest of New Mexico. The range of 73,000 square miles has been estimated assuming that this species is distributed throughout the Apachian Floristic area (Bowers and McLaughlin 1987). The species also may occur in Sonora, Mexico.

Graptopetalum rusbyi is not common and also appears to have sporadic distribution in its range. For example, it has been found in the Rincon Mountains (Bowers and McLaughlin 1987) but not the Tucson Mountains (Rondeau et al. 1996) in Pima County, Arizona. It is also not reported for the Pinaleno Mountains in Graham County, Arizona (Johnson 1988). The Arizona Natural Heritage Program has evidence of a total of 21 occurrences from 6 counties. The populations in New Mexico are at the edge of its range. Plants have not been relocated within the last decade (K. Heil, pers. comm.; R. Sivinski, pers. comm.) but the Xamia butterfly that depends upon Graptopetalum has been observed within the last 10 years, indicating that there are likely extant population(s) of Graptopetalum rusbyi (R. Sivinski, pers. comm.).

At the present time threats to G. rusbyi are unknown. However, G. rusbyi inhabits rocky sites that appear to be fairly inaccessible and unlikely to be affected by livestock grazing, logging, or other similar activities. Although unlikely at the present time, urban development may affect some populations in the future. A potential threat may be from succulent collectors, illegally collecting plants from small populations.