As one enters the Tehuacan-Cuicatlan area in the States of Puebla and Oaxaca, one is confronted with a majestic vista of cereus forests some of whom comprises the largest species of Cacti in existence; Pachycereus weberi. The Tehuacan-Cuicatlan area is one of the richest cacti habitat in the whole of Mexico. This species certainly rivals Carnegea gigantea in sheer volume of branches if not in height.
Its flowers are from pale yellow to white and are produced on the sides of the branches, near the apex. It is mentioned in literature that the flowers are nocturnal but if so they certainly remain open during the day. Pachycereus weberi grows to about 10 meters in height. It starts to branch from approximately two meters from the base and produces candelabra-like branches. Each branch is bluish green in colour and the areoles are spaced from 3 to 5 cm apart.