The article presents the results of a study of five selected taxa of Escobaria (E. missouriensis s.s., E. missouriensis subsp. navajoensis, E. abdita, E. hesteri s.s. and E. minima): the micromorphology of spine surface, the anatomy of their spines in cross section and are discussed as well as macromorphological features. Of the five taxa, E. abdita stands out with its four-layered spine structure in cross section. The spines of the other species show a two-layered structure. The surface structure shows trichomes only in E. missouriensis s.l., whereas these are lacking in E. abdita and other species. The spine anatomy of this genus had not been investigated before. The observations combined with macromorphological features were used for the taxonomic delimitation of the newly described species E. abdita from the group of similar and probably related Escobaria taxa.