[2][3] The genus name comes from the Greek ceras, meaning horn, which refers to the paired, spreading horny projections on the male and female sporophylls of all species.

The whole genus is listed under CITES Appendix I / EU Annex A, which prohibits international trade in specimens of these species except when the purpose of the import is not commercial, for instance for scientific research.

The genus consists of 27 known species:[2][7] C. robusta Miquel C. huastecorum C. zoquorum C. fuscoviridis C. hildae (Bamboo cycad) C. morettii C. mexicana C. decumbens C. latifolia C. microstrobila C. kuesteriana C. mixeorum C. sabatoi C. zaragozae C. matudae C. alvarezii C. norstogii C. vovidesii C. mirandae C. chimalapensis C. euryphyllidia C. whitelockiana C. becerrae C. miqueliana There are several described fossil species, among them †Ceratozamia hofmannii and †Ceratozamia wrightii.

Ceratozamia wrightii is the first evidence of the genus in the fossil record, with leaf fragments of the species found in Eocene deposits on Kupreanof Island in Alaska.

A fossil leaflet fragment of †Ceratozamia floersheimensis from the Rupelian stage of the Lower Oligocene has been found in marine sediments of the Bodenheim Formation in Rauenberg, Baden-Württemberg, Germany.

[10] A fossil leaf fragment of †Ceratozamia hofmannii has been recorded and described from Münzenberg near Leoben (upper Lower Miocene of Styria, Austria.