grows on the Colorado Plateau, principally north Arizona and south Utah, and as its common name suggests is characterized by long (30 inches or more), narrow (half an inch across) leaves, straight-edged, slightly wider in the middle but tapering to a sharp point, topped by a needle-like spine. Long, curling, white filaments grow from the edges, contrasting with the rich green color of the leaves. Plants may develop a short stem, and often form large clusters, but others remain stemless and single.
Four varieties (angustissima, avia, toftiae and kanabensis) are identified by flower properties and leaf length; the two most common are angustissima
found across most of the Colorado Plateau and kanabensis
further west (centered on Kanab).