Pachycereus

Pachycereus groups 10 species of big columnar cactus original from the southwest of the United States and Mexico. They can be solitary but some specimens send branches. The maximum height can be between 4 and 12 m., depending on the species.
Pachycereus pringlei is one of the heaviest cactus.
The name comes from Greek "pachys", thickness. The genus is synonymous of Lemaireocereus and includes Marginatocereus.
Although the bigger plants can tolerate a little cold when they are mature, it is recommended to provide some heat in colder months.
The flowers are funnel shaped and they open at night. The fruits are spiny.