Mammillaria formosa var. microthele (Muehlenpf. & Tiegel) Salm-Dyck, Cact. Hort. Dyck., ed. 1849: 87. 1850
Mammillaria formosa var. microthele, Cact. Hort. Dyck., ed. 1849: 87. 1850
is new combination for Mammillaria microthele in Jahrb. Deutsch. Kakteen-Ges.: 135. 1936