‘Echino’ translates to ‘spiny’; so the genus name of barrel cactus, Echinocactus grusonii, means ‘spiny cactus’. Duh! The nearly spherical and furrowed (ribbed) plants are completely covered with stout and dangerously sharp spines. The most popular variety, known as golden barrel cactus, has pale amber yellow spines. Another variety has white spines. Tan or ruddy spines are rare.
Growth is quite slow. It takes many years for plants to get to three feet tall. Only plants that are quite mature bloom in spring or early summer with bright yellow or orange flowers that develop in a circle, like a halo around the top of the plant. Pink or red flowers are rare. Old plants typically develop a few pups (side-shoots), which may likewise take many years to bloom.
Like most cacti, barrel cactus wants a warm and very sunny location, and very well drained soil. If they do not get watered too much, they can stay potted for many years. However, because they are so nasty, they are not too welcome on porches or patios where most potted plants live. Because they are so heavy and difficult to handle, they are not as portable as they should be.