About Cephalocereus columna-trajani (Karw. ex Pfeiff.) K.Schum.
Cephalocereus columna-trajani (Karw. ex Pfeiff.) K.Schum. produces non-branching green shoots, reaching heights of 6 to 10 meters and diameters up to 40 centimeters. This cactus has 16 to 26 ribs that are almost entirely divided into cusps by transverse furrows. Abundant white, silky hairs grow from the white areoles located near the tip of the shoot. It has 5 to 8 stiff, downward-facing grayish central spines that can reach up to 8 centimeters long, plus 14 to 18 white marginal spines up to 1 centimeter long. The clearly lateral, narrow pseudocephalium is 2 to 3 meters long, extends to the top of the shoot, and is usually oriented toward the north. The pseudocephalium is made up of yellowish, woolly hairs that measure 4 to 6 centimeters long. Its flowers are tubular to bell-shaped, white to light yellow, and reach up to 7.5 centimeters in both length and diameter. Cephalocereus columna-trajani occurs in xerophyllous scrub habitat in the Mexican states of Oaxaca and Puebla, at elevations between 600 and 1800 meters. It forms dense forests in this area, growing alongside Cephalocereus tetetzo, Coryphantha pallida, Mammillaria haageana, and Mammillaria mystax.
