Cereus mortensenii
Cereus mortensenii is a species of plant found in seasonally dry areas of Venezuela. It is the only Cereus species that develops a cephalium.
Description
Cereus mortensenii is a species of treelike cactus that is very branched and reaches heights of up to. The stems are hexagonal and although initially bluish, as they age, they become blue-greenish. They have a diameter of up to and have up to nine ribs.The wooly areoles have 1 to 2 strong central spines of yellowish to gray color and reach a length of 3 to 4 cm. There are also 5 to 7 thin and pointed marginal spines of brown to gray and measure 1 to 1.5 cm long. Mature plants form a thick pseudocephalium
The flowers are creamy white and nocturnal. They measure up to 6 cm long and up to 3.5 cm in diameter. The fruits are spherical and depressed, and are characterized by having adhered flowering remains.