Fishhook cactus has a robust columnar shape, with an internal structure made out of woody ribs. There are around 20 to 30 ribs on each plant. During monsoon season, the ribs expand for easy water storage (2). These cacti tend to lean in a southwest-orientation over time, as the shaded side of the cactus grows faster than the sun-facing side. Wislizeni cacti have a coarse texture resulting from curved red-grey, stiff spines covering the body of the plant. The large spines that protrude from the aeroles, which grow out of the cactus ridges, are variable in color from white to red to gray. The central spines are three to four inches long with hooks on the end.  This species produces red-orange-yellow flowers at the terminal meristems. From these cup-shaped flowers develops scaly, oval-shaped and brilliant, yellow fruits. The fruits are fleshy and contain up to thirty thousand tiny spherical black seeds. They are considered winter evergreen cacti and are listed as "salvage restricted" under the Arizona Native Plant Law. 

The California barrel cactus has been used both as a food source and for trade by indigenous people of the American Southwest. The Apache, Papago and Seri use the juice the seed can be ground, boiled and turned into a paste for consumption. The spines are used for hunting by heating and then bending them or to make hooks for fishing (4).  The fleshy tissues of the cacti are consumed by big horn sheep during seasonal droughts (1) and the plant is a striking accent plants in desert landscapes.