Largest barrel cactus species

The most widely accepted largest species of barrel cactus is the candy barrel cactus or giant barrel cactus (Echinocactus platyacanthus) native to the Chihuahuan Desert of central Mexico, which can grow up to 2.5 metres (8 feet 2 inches) tall and 1 metre (3 feet 3 inches) in diameter. A similar upper limit has been documented occasionally for Emory's barrel cactus (Ferocactus emoryi).

Barrel cacti are so-named for their distinctive ribbed, rounded form, which can be cylindrical or more globular. They fall into two genera of cactus: Echinocactus and Ferocactus.

Known locally as biznaga, E. platyacanthus has been harvested for consumption by both humans and as fodder for livestock since prehistoric times. Its pith, in particular, is boiled to make the traditional Mexican candy acitrón.