What is the name of this tree?

You see this a lot around here (northern California) and I like it but still haven't found its name. The trunk can get pretty big, it's a real tree.

Looks like Yucca, or Cordyline, but I think its different. Note how the leaves do not grow in a star shape from one point, rather they grow perpendicular to the stem for the last few feet of stem (not only the tip)

Thanks for your help!