Echinocactus

Echinocactus or Barrel Cactus  is a small genus of cacti that includes 5 accepted species that are indigenous to the Southwestern United States and Mexico. In the past, this genus included hundreds of species, but in the 1900s, noted cactus taxonomists, Nathaniel Britton and Joseph Rose, moved most species into different genera. The famous golden barrel cactus is now correctly called Kroenleinia grusonii. The genus name, Echinocactus, originates from the Greek words echinos, meaning "hedgehog," and kaktos, meaning "thistle." This genus is known for its rounded, ball-like shape that may elongate with age. It is a member of the cactus family (Cactaceae).

These plants grow best in full sun, but they can tolerate a little bit of shade.  They prefer low humidity, dry soil, and need a cactus mix with coarse sand or perlite to promote good drainage. 

The species in this genus have robust spines and yellow or pink funnel-shaped flowers. The fruits vary from dry and wooly to fleshy and round.  Many cultivars exist with unusual knobby or fasciated growth, and all have many spines. They vary greatly in size and are much smaller when grown in a pot. 

The plant can be easily grown as a houseplant in a container, and it is tolerant to a wide array of conditions.  

Quick ID:

• Ball-like or barrel-like shape
• Clearly defined rows of vertical ribs with long, sharp spines
• Wool-like fuzz at the top of the stem where the flowers emerge
• Funnel-shaped flowers with numerous petals

Insects, Diseases, and Other Plant Problems:. May be susceptible to aphids, mealybugs, scale, and whiteflies. Overwatering can cause root rot.

VIDEO Created by Laura Barth for "Houseplants, Succulents, and Cacti," a plant identification course offered in partnership with Longwood Gardens.