Sclerocactus glaucus

Sclerocactus glaucus is a rare species of cactus known by the common name Colorado hookless cactus. It is endemic to Colorado in the United States, where it is known only from the area between Grand Junction and Montrose. It is a federally listed threatened species. The description of this species formerly included plants now belonging to Sclerocactus brevispinus and Sclerocactus wetlandicus, two cacti endemic to Utah. When the second of the two species was separated in 1994, the name S. glaucus was applied only to plants found in Colorado; it made the common name Uinta Basin hookless cactus a misnomer, because now this species does not occur in the Uinta Basin of Utah. The two new species retained their federally threatened status, which they had received while members of S. glaucus. Sources vary in whether they recognize the separation of these species from S. glaucus; Anderson (2001) does not. This cactus is cylindrical in shape and measures up to 28 centimeters tall by 9 wide, thou......read more on Wikipedia.