Agave

"Each Agave rosette is monocarpic and grows slowly to flower only once. During flowering, a tall stem or "mast" ("quiote" in Mexico) grows from the center of the leaf rosette and bears a large number of short, tubular flowers. After development of fruit, the original plant dies, but suckers are frequently produced from the base of the stem, which become new plants."

Flowers are just starting to open on this agave.
There are usually mixed feelings about the flowering since the plant will die but the mast and flowers really are spectacular.
Sorry for the poor quality- cell phone camera in low light. And my ability. :)