Aeonium haworthii Webb & Berthel. and Crassula ovata (Mill.) Druce (Crassulaceae): New records for the Algerian alien flora

This paper expands the list of alien species of Crassulaceae that escaped from cultivation in Algeria and mainland North Africa, as a result of the discovery of two new alien species in the Skikda region (northeastern Algeria) in 2021 and 2023.Aeonium haworthii was recorded in a semi-natural habitat, the maritime cliff of the Stora region, and seems completely naturalized in this locality.Crassula ovata was recorded in an urban environment, where it colonizes balconies and roofs; at present, this species is considered to be a casual.These results are supported by field photos of both species, a distribution map and an updated list of alien Crassulaceae species reported so far from mainland North Africa (Algeria, Morocco and Tunisia).