“Head candle” referring to the pseudocephalium near top of the stems in this genus, resembling a head.
A genus of treelike, columnar erect plants, solitary or sparsely branched, branching usually from the base, with the areoles close each other. Many radial spines, setose, or with long hair which sometimes cover the entire epidermis.
Flowers nocturnal, self-sterile, tubular to bell-shaped, produced in a pseudocephalium, white-pinkish to pink tinged yellow, pollinated by bats (Choeronycteris mexicana, Leptonycteris curasoae, L. nivalis, L. yerbabuenae). Fruits ovoid with small scales and wool. Seeds pyriform (pear-shaped), shiny, black.
The genus Cephalocereus grows endemically in Mexico, in colonies which typically dominate the landscape, in ravines, sometimes growing on steep slopes, on rocky islets, on various types of soils, depending on species, composed of limestone (C. columna-trajani) or quartz (C. aplclcephalium), sandstone, mica or even andesite (C. totolapensis) from about 1000 m up to 1850 m in altitude, with other cacti and succulents. Cephalocereus senilis is a very common garden plant when young.
Mexico (Chiapas, Guanajuato, Hidalgo, Oaxaca, Puebla, Veracruz).
Currently 5 recognised species:
– Cephalocereus apicicephalium* e.y.Dawson 1948
– Cephalocereus columna-trajani* (Karw. ex Pfeiffer) K.Schum. 1894
– Cephalocereus nizandensis (Bravo & Macdoug.) F.Buxb. 1965
– Cephalocereus senilis* (Haw.) pfeiff. 1838
– Cephalocereus totolapensls* (Bravo & Macdoug.) Buxb. 1965 (although the latter is declared invalid because, according to Hunt, no type was designated).
References: "TAXONOMY of the CACTACEAE" - ISBN 978-84-617-3723-9 (Vol. 1)