Coryphantha robustispina, coryphantha sheeri ssp robustispina
Robust spine beehive cactus, long-tubercle beehive cactus, Pima pineapple cactus
Southeast Arizona (around Nogales and on the eastern slopes of the Chiricahua Mountains), scattered locations in south New Mexico, and along the Rio Grande in west Texas
Spherical, slightly flattened stems, forming small mounds
Varied; scrubland, grassland, dry washes, woodland up to 6,000 feet
Pale yellow, with light red stripes
Although small, coryphantha robustispina has an unusual, distinctive appearance, its compact globes covered by extra long tubercles bearing especially thick spines; both radials (6 to 16) and the slightly curved centrals (1 to 4) are stout, darkish in color and point in all directions, creating a very spiny plant. The yellow flowers open any time between spring and early fall, triggered by rainfall.
Three varieties of the cactus are recognized (robustispina, scheeri, uncinata), but all are rare, and the species is listed as endangered.