The Nichol Turk's head cactus ranges from blue-green to yellow-green. It is a barrel cactus, reaching a maximum height of 18 inches and diameter of eight inches.1 It has eight ribs which spiral on the trunk. Spines are found on the ridges of the plant, with three central spines and five radial spines.1 The flowers are bright purple and bloom from April to May. The fruits are covered with white, wooly hairs.2 This cactus is very slow-growing, taking ten years to reach a height of two inches.3
This species occurs in semi-arid Sonoran desert scrub. It persists on limestones outcropping and limestone derived soils in incline terraces, saddles, and alluvial fans at elevations from 2,400 to 4,100 feet.1
The range of the Nichol Turk's Head Cactus is restricted to the Vekol and Waterman Mountains in Arizona and to a population in the Sierra del Viejo Mountains of northwestern Sonora, Mexico.1
This species was listed endangered in 1976 and has an approved recovery plan. It is also protected from international trade by the Convention on International Trade in Endangered Species of Wild Fauna and Flora and by the Arizona Native Plant Law.2 The cactus is threatened by mining, off-road vehicle use, collecting, and in some cases, human encroachment.
Nichol Turk's Head in Pima County:
The cactus occurs in the Waterman Mountains of north-central Pima County.2 In these mountains, mining, off-road vehicles, and collectors have negatively affected several populations of Nichol Turk's head. In order to remove this species from the endangered species list, natural populations of this plant must be maintained, protected, and if possible, enhanced.1
1. U.S. Fish and Wildlife Service. 1986. Nichol Turk' s Head Cactus (Echinocactus horizonthalonius var. nicholii) Recovery Plan. Albuquerque, New Mexico.
2. U.S. Fish and Wildlife Service. 1998. Threatened and Endangered Species of Arizona. Arizona Ecological Service Field Office. Phoenix, AZ. pp. 21-22.
3. Arizona Game and Fish Department. 1994. Echinocactus horizonthalonius var. nicholii. Unpublished abstract compiled and edited by the Heritage Data Management System, Arizona Game and Fish Department, Phoenix, AZ. Albuquerque, New Mexico.
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