In continental Portugal, Sedum mucizonia (Ortega) Raym.-Hamet (Crassulaceae), a miniature, annual succulent, is known to occur especially in southern and central-western coastal areas, as well as along the central- and southeastern border between Portugal and Spain. Current records indicate that its northwestern-most limit in central Portugal is in the Parque Natural das Serras de Aire e Candeeiros, in the province of Estremadura. With at least 35% of the Crassulaceae species known from Portugal having been recorded from this region, it is established as a significant present-day centre of diversity for the family in the country. In addition to a distribution map for S. mucizonia in central continental Portugal, illustrations of the species are provided for the various locations from which the species has been collected in that part of the country. We also establish beyond doubt the location of the type locality of S. mucizonia, which is at San Sebastian, near Puertollano in the province of Ciudad Real, in Spain.