You don't mention your location or exposure so will guess on basis of the Toyon suggestion. Growing in native soil without summer water the Toyon here in full sun will often not grow over 6 feet. You might consider the "Bush Poppy" Dendromecon harfordii or rigida. Either can be kept to 6 feet, but will probably be a little harder to get established. Al

A native I really like that's evergreen, easy care, unfussy and has lovely red flowers that the hummers like is galvezia (bush snapdragon). Books say they'll get to about 4 feet tall and around which is where mine are right now. I'm wondering if I leave it alone if it'll get a little bigger. These pix don't do the plant justice. It's much prettier.

http://www.californianativeplants.com/index.php/plants/featured-plants/48-galvezia

Another native I've been really surprised by is the Winifred Gilman cleveland sage. I prefer the darker color of the flowers to the regular cleveland sage. I got some in 4-inch pots and I can't believe how quickly they established. I also like how the foliage on the Winifred Gilman is a little greener, or so it seems to me, and denser. Gets to 5 feet tall and around.

http://www.yerbabuenanursery.com/viewplant.php?pid=0208

A nice non-native that is also wonderfully drought tolerant, gives a soft vertical accent in the garden and has a kind of sage-y wild look, is evergreen, and has light lavender flowers spring, summer and fall is coast rosemary (westringia)"wynyabbie gem". Mine are about 5 feet tall and would be about as wide if I didn't trim them up a smidge so they have a slimmer profile.

http://www.mostlynatives.com/notes/westringiarosmariniformis.htm