About Ferocactus robustus (Karw. ex Pfeiff.) Britton & Rose
Ferocactus robustus (Karw. ex Pfeiff.) Britton & Rose forms large cushions, growing up to 100 centimetres (39 in) tall and up to 5 metres (16 ft) in diameter. Individual plants are spherical to club-shaped, and have eight sharp-edged, tuberous ribs with diameters of 8 to 16 centimeters. The areoles, which produce the thorns, are widely spaced. The reddish or purple thorns consist of four to seven strong, protruding, straight central spines that grow up to 6 centimeters long, plus 10 to 14 lighter-colored radial spines. The upper radial spines resemble the central spines, while the lower radial spines are bristle-like. Its funnel-shaped flowers are yellow and reach 3–4 centimetres (1.2–1.6 in) in length. The fruits are spherical, fleshy, yellow, and 2 to 3 inches long. Ferocactus robustus is widespread across the Mexican states of Puebla and Veracruz, growing at elevations between 700 and 1000 meters.
