Melocactus praerupticola Areces subsp. Pygmaeus (Hoxey, Gdaniec et Ackerman) Areces comb. et stat. nov.: Review of the Miniature Mountain Melocactus Populations of the Greater Antilles

Though they are morphologically very similar, the two unique mountain populations of miniature Melocactus from Puerto Rico and Hispaniola (Dominican Republic) have been treated as different species. After contrasting several living plants and their cultivated descendants from both island-sites over the years, it is concluded that the minor vegetative differences that separate them do not justify species recognition. As a result, the recently described Melocactus pygmaeus Hoxey, Gdaniec and Ackerman from the steep slopes of Sierra de Cayey, Puerto Rico is hereby treated as a subspecies of the previously described Melocactus praerupticola Areces from the rocky cliffs of Constanza, in the central mountains of the Dominican Republic. Likewise, based on vegetative and floral characters, no apparent similarities were found between this praerupticola–pygmaeus complex and M. guitartii León from Cuba.