The thorns can almost completely cover the body, are long, stiff, curved to straight, sometimes hooked, light brown to horn-colored, darker in new growth and later graying.

The color of the petals varies between white, pink, purple, yellow and orange, the stamens are yellowish and protrude above the greenish hubs.

The flower tube is greenish with pointed scales, the axils of which appear darker and are covered with gray wool.

The first description was made in 1922 by Nathaniel Lord Britton and Joseph Nelson Rose.

[4] The specific epithet ferox comes from Latin, means 'wild' and refers to the thorns of the species.