Commonly called Dragon Tree, it's a species of Dracaena, probably D. draco. They get up to about 10 or more metres tall.

Ah, I was thinking maybe a Dracaena, thanks for the confirmation!

Christopher

Dracaena but definitely not D. drago...

That's a really big- huge,D. marginata. The same houseplant that takes dim light all over America.
In soucal and Florida they reach a good size. In the bay area I've seen some so far about the size of a large branch on the pictured plant outdoors.