Cereus mortensenii

Cereus mortensenii is a species of plant found in seasonally dry areas of Venezuela. It is the only Cereus species that developes a cephalium.

Cereus mortensenii
Conservation status
Near Threatened  (IUCN 3.1)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Order:	Caryophyllales
Family:	Cactaceae
Subfamily:	Cactoideae
Genus:	Cereus
Species:	C. mortensenii
Binomial name
Cereus mortensenii (Croizat) D.R.Hunt & N.P.Taylor[1]
Synonyms
Pseudopilosocereus mortensenii Pilosocereus mortensenii Pilosocereus gruberi

Description

Cereus mortensenii is a species of treelike cactus that is very branched and reaches heights of up to 8 metres (26 ft). The stems are hexagonal and although initially bluish, as they age, they become blue-greenish. They have a diameter of up to 8 centimetres (3.1 in) 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.^[2]

Taxonomy

This plant is sometimes placed in the genus Pilosocereus because of its cephalium.

Etymology

This plant is named for Russell H. Mortensen who helped with the discovery and collection of this species ^[3]