(This plant comes in a 3.5" pot. You will receive a very similar plant to the one in the picture. It may or may not be blooming at the time of your purchase. The plant is shipped in its pot to prevent any damage to the roots).
Calibanus hookerii is an interesting looking plant that is related to the agaves, topped by perennial grass like silver-blue leaves that expand from a woody caudex (Swollen succulent root).
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz