Resumen

ARIAS, Salvador  y  TERRAZAS, Teresa. xPachebergia (Cactaceae), a nothogenus from western Mexico. Rev. Mex. Biodiv. [online]. 2008, vol.79, n.1, pp. 23-28. ISSN 1870-3453.

xPachebergia (Backebergia x Pachycereus), a new nothogenus from western Mexico, is proposed. Stem and seed morphology of this poorly known taxon from dry to very dry deciduous tropical forest in the Balsas River Basin, Guerrero, are described and illustrated. Its diagnostic morphological characters and relationships with Pachycereus pecten-aboriginum and Backebergia militaris, its putative parental taxa, are discussed.

Palabras llave : Backebergia; Balsas River Basin; hybrid; new nothogenus; Pachycereus.