Shindagger (Agave schottii)

DESCRIPTION: Perennial to 1.5', flower stalk to 8'. Flowers to 1" wide, yellow, tubular (to 2.5" long) in clusters along tall stalk. Leaves a basal rosette, linear (often curved) to 16" long. Leaves have a spine only at tip, not along edges. Agavaceae (Agave) Family.
NATURAL HISTORY: Flowers bloom May to October. The plant is well-named; a poke in the shin (or anywhere else for that matter) is a very painful experience!