I have a very healthy pot tree right outside my office window. See the leaf? OK, it's not really a pot tree--it's something called a vitex. Interestingly, one of its common names is hemp tree, but I am assured that its leaves have no hallucinogenic properties. Darn. :) Well, at least it's pretty. The smaller pic below the big leaf shows a full grown tree (ours are still quite young) and the "cone" of purple flowers it sprouts all over.
In the same courtyard with the pot tree, there are cat mint plants like the one below, which also has purple flower "cones". Oddly enough, I've yet to see a single cat hanging around them. Plenty of jackrabbits, but no cats. Such a waste!