Wright Fishhook Cactus

Sclerocactus wrightiae

Description

Wright fishhook cactus, Sclerocactus wrightiae, is formed of several unbranched stems, each about 2 to 3 in (5 to 7.5 cm) in diameter with about a dozen ribs. Spine clusters (areoles) have four central spines, the lowest of which is sharply hooked. Eight to 10 radial spines on each areole are white. The fragrant flower has reddish brown, reddish green, or lavender centers with pale pink to white margins. Flowers develop when plants are still quite small, forming on new growth. Blossoms cluster at the top of each barrel. Specific pollinators are not known, but a small beetle has been observed in closed flowers.

Reproduction is primarily by seed. The fruits mature in June, dispersing seeds near the base of the parent plant. As the summer progresses and conditions become drier, the cactus shrinks, becoming almost level with the ground surface.

This cactus has also been known by the scientific name Pediocactus wrightiae.

Habitat

Unlike many of Utah's native cacti, which are restricted to a narrow habitat, such as a single geologic subformation or soil type, Wright fishhook cactus is less demanding in its requirements. It can be found in various soils of the Mancos shale formations, ranging from Blue Gate clays to sandy silts or on the fine sands of Ferron and Entrada sandstones. Some sites have well-developed gypsum layers, others have little or no gypsum. Common to most sites is a litter of sandstone or basalt gravels, cobbles, and boulders.

The habitat is semi-arid, with widely spaced shrubs, perennial herbs, bunch grasses, pinyon, and juniper.

Distribution

The historic range of the Wright fishhook cactus extends in an arc from Emery (Emery County), Utah, through the Goblin Valley region to Hanksville (Wayne County), about 50 mi (80 km) to the southeast. This range lies in the Canyonlands section of the intermountain region, a low-elevation desert trough that curves around the southern end of the San Rafael Swell.

When the species was listed in 1979, it was known from five locations on public lands managed by the Bureau of Land Management (BLM) or on state lands. Later surveys located additional populations in 25 townships in Wayne and Emery Counties. Most of these populations consist of only scattered individuals. Where there is good habitat, populations can be almost continuous, although individual plants are widely dispersed. The populations can be divided into two general areas: the Emery area and the Caineville-Hanksville area. A thorough inventory and population count has not yet been conducted.

Threats

This cactus, like many others, is threatened by illegal collecting. However, because populations are widely dispersed, it is difficult to collect on a commercial scale. Finding the plants over such a large area is more time-consuming than taking a more readily available species, such as the federally listed Uinta Basin hookless cactus (Sclerocactus glaucus ).

Because the cactus' range lies within an area with known coal resources near Emery, habitat loss to coal mining development is a potential threat. The Environmental Impact Statement produced to support the region's designation as a coal resource area made no mention of the Wright fishhook cactus.

In the Caineville-Hanksville area, off-road vehicle traffic has damaged some plants and contributed to harsh erosion patterns, and cattle have trampled plants at several sites. A proposal to designate the area a "wilderness study area" was dropped because of widespread protest.

Conservation and Recovery

The Fish and Wildlife Service's Recovery Plan for the Wright Fishhook Cactus sets the goal of establishing two separate and self-sustaining populations of 10,000 plants each before the cactus is reclassified from Endangered to Threatened.

Contact

Regional Office of Endangered Species
U.S. Fish and Wildlife Service
Denver Federal Center
P.O. Box 25486
Denver, Colorado 80225
http://www.r6.fws.gov/

References

Anderson, J. 1982. "Travel Report on Cactus Investigations, April 28-30." Report. U.S. Fish and Wildlife Service, Denver.

Heil, K. D. 1979. "Three New Species of Cactaceae from Southeastern Utah." Cactus and Succulent Journal 51:25-30.

U.S. Fish and Wildlife Service. 1985. "Wright Fish-hook Cactus Recovery Plan." U.S. Fish and Wildlife Service, Denver.

Woodruff, D., and L. Benson. 1976. "Changes in Status in Sclerocactus." Cactus and Succulent Journal 48:131-134.