Pelecyphora chihuahuensis (Britton & Rose) D.Aquino & Dan. Sanchez comb. nov.

Escobaria chihuahuensis ≡ Escobaria chihuahuensis Britton & Rose, Cactaceae 4: 55. 1923. Coryphantha chihuahuensis (Britton & Rose) A.Berger, Kakteen: 339. 1929. Escocoryphantha chihuahuensis (Britton & Rose) Doweld, Sukkulenty 2: 10. 1999. Type: México, Chihuahua, Vicinity of Chihuahua, 08 Apr 1908, E. Palmer 72 (holotype: US [573550]; isotype: K [250731 image!]).

Mammillaria strobiliformis = Mammillaria strobiliformis Scheer ex Salm-Dyck, Cact. Hort. Dyck. 104-105. 1850, not Mammillaria strobiliformis Engelm., Mem. Tour N. Mexico: 113. 1848, not Mammillaria strobiliformis Muehlenpf., Allg. Gartenzeitung 16: 19. 1848. Echinocactus strobiliformis Poselg., Allg. Gartenzeitung 21: 107. 1853. Cactus strobiliformis (Sheer) Kuntze, Revis. Gen. Pl. 1: 261. 1891. Escobaria strobiliformis (Poselg.) F.Boedeker, Mammillarien-Vergleichs-Schlüssel 16. 1933. Coryphantha strobiliformis (Poselg.) Moran, Gentes Herbarium 8: 318. 1953. Type: [Fragments from] Potts’s original specimen, cult. 1857, hort., Jan 1857, J.M.F.A.H.I.Salm-Reifferscheid-Dyck s.n. (lectotype, designated by Benson, Cact. Succ. J. (Los Angeles): 189. 1969: MO). Notes. Britton and Rose (1923) chose Engelmann’s epithet tuberculosa over strobiliformis, because the last represents a homonym. However, Benson (1969) suggested that the epithet strobiliformis should be preferred over the epithet tuberculosa. Zimmerman and Parfitt (1993+) mention that Escobaria tuberculosa and E. strobiliformis represent two independent entities and the name E. chihuahuensis Britton & Rose should be considered a synonym of E. strobiliformis . Given the difference in opinions, Hunt et al. (2006) explained that the name Escobaria strobiliformis has been incorrectly applied to E. tuberculosa and should be rejected. Hunt (2016) concludes that E. strobiliformis is an inadmissible name or with indeterminate application. In order to maintain the stability of the names listed in this treatment, the name Mammillaria strobiliformis is considered a homonym and should not be applied (Turland et al. 2018). In turn, this decision makes it possible to retain the epithet strobiliformis for the name Pelecyphora strobilformis (Werderm.) Fric. & Schelle (basionym Ariocarpus strobiliformis Werderm.). Finally, original description is not complete and lacks data on floral characters, so it is not feasible to decide on the correct interpretation.

Mammillaria strobiliformis caespititia = Mammillaria strobiliformis var. caespititia Quehl, Monatsschr. Kakteenk. 19: 173. 1909. Mammillaria strobiliformis f. caespititia (Quehl) Schelle, Kakteen: 285. 1926. Escobaria tuberculosa var. caespititia (Quehl) Borg, Cacti 304. 1937. Type: Probably Mexico. (Not preserved).