- barrel cactus - 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
--1 is a kind of cactus
--1 is a member of Ferocactus, genus Ferocactus- echinocactus, barrel cactus - any cactus of the genus Echinocactus; strongly ribbed and very spiny; southwestern United States to Brazil
--2 is a kind of cactus
--2 is a member of genus Echinocactus
--2 has particulars: hedgehog cactus; golden barrel cactus, Echinocactus grusonii - echinocactus, barrel cactus - any cactus of the genus Echinocactus; strongly ribbed and very spiny; southwestern United States to Brazil