PIMA PINEAPPLE CACTUS } Coryphantha scheeri var. robustispina
FAMILY: Cactaceae

DESCRIPTION: From a distance, the Pima pineapple cactus resembles a small barrel cactus. It is distinguished by its large, knoblike sections and by clusters of several small, straight spines surrounding one straw-colored, hooked central spine. With silky, yellow flowers and sweet, green fruit, it measures up to 18 inches tall and seven inches in diameter and is found both alone and in groups.

HABITAT: The Pima pineapple cactus grows in semi-desert grassland and Sonoran Desert scrub. It occurs in open, relatively flat areas at elevations below 4,000 feet.

RANGE: This cactus has an extremely limited range in southeastern Arizona and in northern Sonora, Mexico. Within its range, which measures just 45 miles east to west and 50 miles north to south, it is sparsely distributed and averages less than one plant every four acres.

BREEDING: The flowers of the Pima pineapple cactus appear in early July with the summer monsoon rains. Flowering continues until August, followed by green, oval fruit.

THREATS: Habitat loss is a major threat to this species, resulting from urban development, off-road vehicles, road construction, livestock grazing, agriculture, and mining. Other threats include illegal collecting and the proliferation of nonnative grasses, which prevent new plants from taking root. It is estimated that up to 75 percent of the Pima pineapple cactus's current range could be lost due to urban development around Tucson.

POPULATION TREND: In 1975, the Smithsonian Institution recommended that the Pima pineapple cactus be listed as threatened. Yet the cactus languished unprotected for years as populations further declined. It was finally listed as an endangered species in 1993. Today, only 1,500 individual cacti remain in the United States. In 2002, the Pima County Board of Supervisors set aside 590 acres as a mitigation bank for the Pima pineapple cactus.

Photo © Lorena B. Moore