Malacothamnus (bush-mallow) is a genus of shrubs and subshrubs found throughout much of mainland California and on three of the Channel Islands. Outside of California, Malacothamnus is known from the northern half of Baja California, from a disjunct location in central Arizona, and possibly from a historic location that may have been in southern Arizona or adjacent Mexico. Plants of this genus are most commonly found in early-successional, post-burn plant communities. Malacothamnus are currently thought to be most closely related to the Iliamnas of the US interior and the Phymosias of Mexico, Central America, and the Caribbean.