[1] An evergreen perennial, it forms large, dense rosettes of grey-green, strap-like leaves edged with hooked spines.

The green or yellow flowers are borne on spikes which resemble a medieval mace, and stand up to 2 m (6 ft 7 in) high.

The outer two-thirds of the leaf blade bears outward-pointing spines which may be an adaptation to prevent herbivores from reaching the center of the plant.

[3] It is commonly found on arid hillsides of the Andes, on north-facing slopes of matorral areas at 300–1,000 m (980–3,280 ft) above sea level.

In its natural arid environment, plants can be highly flammable and are susceptible to damage from fires that are often the result of human action.