Abstract
Graptopetalum rosanevadoensis (subgenus Glassia, Crassulaceae), a new haplostemonous species from Jalisco, Mexico, is described and illustrated. Its closest morphological species are G. superbum and G. pentandrum. It differs from both in having a much larger rosette with more numerous leaves and in terms of its number of branches per panicle and its stem diameter, which is intermediate between the two species. Now, subgenus Glassia includes four allopatric haplostemonous species, all confined to western-central México: G. glassii, G. pentandrum, G. rosanevadoensis and G. superbum. A key to species of Graptopetalum, subgenus Glassia is provided. According to IUCN criteria, the species was assessed as critically endangered (CR).