Pediocactus peeblesianus

Pediocactus peeblesianus is a rare species of cactus known by the common names Navajo pincushion cactus. It is endemic to the state of Arizona in the United States. The species is named after the Arizona botanist Robert Hibbs Peebles.

Description
This petite cactus grows up to 6.5 centimeters tall by about 5.5 wide. It is grayish green in color and generally spherical or egg-shaped. Sometimes only the top is visible above the soil and the whole cactus body may shrink and disappear under the soil in dry times. Each circular, hairy areole on the surface of the cactus has a few spines, the longest of which may exceed 2 centimeters in length, marginal spines are 2 to 10 mm long. The spines are mostly corky and flexible but have hard tips and are white or dull in color. The funnel-shaped yellowish flowers are up to 2.5 centimeters wide blooming from April to May. The fruit is green, ripening reddish-brown, reaches about a centimeter long, and contain about 5 to 10 dark brown to black seeds.

Subspecies
This species is divided into two subspecies, but these are sometimes referred to as varieties. One subspecies of the plant is federally listed as an endangered species of the U.S.

Habitat
The species occurs in desert habitat and the transition to Great Basin grassland habitat at elevations of 1450 to 1600 meters. It grows in sandy soil and among rocks. Drought has been a significant threat to this cactus in recent years.