Endangered Species
Mountain-Prairie Region


Colorado Hookless Cactus

Photo by Gina Glenne

The Uinta Basin hookless cactus has been protected under the Endangered Species Act (Act) since 1979 (44 FR 58868), until recently it was considered a part of S. glaucus (Uinta Basin hookless cactus). On September 15, 2009 (74 FR 47112), the U.S. Fish and Wildlife Service officially recognized the taxonomic split of this species into three distinct species:  S. brevispinus (Pariette cactus), S. glaucus (Colorado hookless cactus), and S. wetlandicus (Uinta Basin hookless cactus).

The common name for S. glaucus was changed to Colorado hookless cactus as the species is endemic to western Colorado. S. wetlandicus is now known as the Uinta Basin hookless cactus as this species occurs across Utah’s Uinta Basin. S. brevispinus is now known as the Pariette cactus as it is limited to the Pariette Draw of the Central Uinta Basin.  This webpage will refer to the Colorado hookless cactus’ common name to avoid confusion.

Colorado hookless cactus is a barrel-shaped cactus that ranges from 4 to 18 centimeters (1.5 to 7 inches ).  The stems have typically 12 to 15 ribs that extend from the ground to the tip of the plant.  The funnel-shaped flowers usually have pink to violet tepals with yellow stamens, and are 2 to 5 cm (0.8 to 2 in.) long and 2 to 5 cm (0.8 to 2 in.) in diameter (74 FR 47112). The fruit is short, barrel-shaped, reddish or reddish grey when ripe, 7 to 12 mm (0.3 to 0.5 in.) wide, and 9 to 25 mm (0.35 to 1.0 in.) long.  Colorado hookless cactus is generally found on coarse soils derived from cobble and gravel river and stream terrace deposits, or rocky surfaces on mesa slopes at 1,350 to 1,900 meters (4,400 to 6,200 feet) in elevation.

At the time of the original listing of the Colorado hookless cactus complex, ongoing and foreseeable threats included mineral and energy development, illegal collection, recreational off-road vehicle use, and grazing.

In April 2010, we completed a recovery outline for the species. This document lays out a preliminary course of action for the recovery of the Colorado hookless cactus. It serves to guide recovery efforts and inform consultation and permitting activities.

Last updated: January 17, 2017