Mammillaria elongata DC. subsp. elongata in Mém. Mus. Hist. Nat. 17: 109. 1828 sec. Hunt 2016
- =Mammillaria densa Link & Otto in Icon. pl. rar. 1830: 69. 1830 syn. sec. Guzmán & al. 2003
- =Cactus elongatus (DC.) Kuntze, Rev. Gen. Pl. 1: 260. 1891 syn. sec. Guzmán & al. 2003
- =Neomammillaria elongata (DC.) Britton & Rose, Cactaceae (Britton & Rose) 4: 134. 1923 syn. sec. Guzmán & al. 2003
- =Chilita elongata (DC.) Orcutt, Cactography 2. 1926 syn. sec. Guzmán & al. 2003
- =Leptocladodia elongata (DC.) Buxb. in Oesterr. Bot. Z. 101: 601. 1954 syn. sec. Guzmán & al. 2003
- =Mammillaria elongata var. densa (Link & Otto) Backeb., Cactaceae (Backeberg) 5: 3258. 1961 syn. sec. Guzmán & al. 2003
- =Krainzia elongata (DC.) Doweld in Sukkulenty 3: 43. 2000 syn. sec. Guzmán & al. 2003