barrel cactus

(noun) a cactus of the genus Ferocactus: unbranched barrel-shaped cactus having deep ribs with numerous spines and usually large funnel-shaped flowers followed by dry fruits. Synonyms: barrel cactus.

(noun) any cactus of the genus Echinocactus; strongly ribbed and very spiny; southwestern United States to Brazil. Synonyms: echinocactus, barrel cactus.