Here is an agave that is giving its lasts hurrah. They live for twenty years looking like the lower part of this image then in the twentieth year they send up this center. It takes a few months from the time it starts growing, getting the side buds then flowers. When it is all done blooming the plant dies.
However, there are new babies along the base to continue the process.
Sorry for the poor scan but the page is 9x12 inches and it doesn't quite fit in the scanner.