A pic says a thousand words, and I have many. ;o)
ferocactus, covered in the winter.
Yucca rostrata, with winter burn this year.
Yucca baccata, a very big one, long leaves!
This is an amazing yucca. It is a hybrid of some kind. He said it was bought as 1 gal. Yucca thompsoniana.
To the right is your average sized Y. thompsoniana/rostrata, look how it dwarfs the other yuccas.