Synonymity according to Britton & Rose:

  "While this plant shows considerable variation in its spines, we do not believe it possible to separate the species into varieties as Schumann has done.

  Echinocactus jeneschianus Pfeiffer (Allg.. Gartenz, 8: 406. 1840) and Echinocactus pepinianus echinoides (Labouret, Monogr. Cact. 177. 1853) are referred to Echinocactus echinoides by Labouret.
  Echinocereus chiloensis Console and Lemaire (Rev. Hort. 35:173. 1864) is only mentioned, but Lemaire later (Cact. 61. 1868) states that it is based on Cereus chiloensis, which definitely places it here.
  Cereus chilensis junkianus (Schumann, Gesamtb. Kakteen 61. 1897) has never been formally published.
  Cereus polymorphus (published as a synonym of Opuntia polymorpha in Forster, Handb. Cact. 472. 1846), referred here by Schumann, should doubt­less go elsewhere, for it is said to come from Mendoza, Argentina. It may be a form of Opuntia glomerata.
  Cereus pycnacanthus Salm-Dyck (Allg. Gartenz 13: 355. 1845), and Cereus panoplaetus Cels (Salm-Dyck, Cact. Hort. Dyck. 1849. 44. 1850) published as a synonym of the former, were both referred to Cereus chilensis by Schumann, but they came from Bolivia and the description does not fit this species.
  Cereus fulvibarbis Otto and Dietrich (Allg. Gartenz. 6: 28. 1838; Cereus chilensis fulvibarbis Salm-Dyck in Walpers, Repert. Bot. 2: 276. 1843), said to have come from Chile, is referred to Cereus chilensis by Schumann, but it isdescribed as having 10 to 13 ribs.
  Cereus polymorphus G. Don (Loudon, Hort. Brit. 195. 1830) and Cactus polymorphus Gil­lies (published here as a synonym), referred to Cereus chilensis by Schumann, can not be iden­tified from the meager description. It is said to have been introduced from Chile in 1827.

  The following names belong here; they have not been accompanied by descriptions.
Cereus quintero Pfeiffer, Enum. Cact. 86. 1837.
             chilensis brevispinulus Salm-Dyck in Walpers, Repert. Bot. 2:276. 1843.
                             spinosior Salm-Dyck in Forster, Handb. Cact. 377. 1846.
                             flavescens Salm-Dyck, Cact. Hort. Dyck. 1849.44. 1850.
                             eburneus (Schumann, Gesamtb. Kakteen 63. 1897) based on Eulychnia eburnea Philippi, must belong here.
                             linnaei Schumann, Gesamtb. Kakteen 63. 1897.
                             quisco Weber Hirscht, Monatsschr. Kakteenk. 8:110. 1898.

  Cereus spinibarbis var. minor Monville and var. purpureus Monville (Labouret, Monogr. Cact. 334. 1853) have been referred here.
  Cereus elegans Lemaire and C. duledevantii Lemaire (Illustr. Hort. 5: Misc. 10. 1858), unpublished, doubtless were given to forms of this species.
  Echinocactus pyramidalis and E. elegans (Pfeiffer, Enum. Cact. 86. 1837) were given only as synonyms of Cereus chilensis."