Pacific poison-oak
Toxicodendron diversilobum
Anacardiaceae

Poison-oak really is quite showy and beautiful. I'd wear shorts and water sandals more often for my hikes if it wasn't so ubiquitous. Thank goodness I'm not familiar with the "fun" of the allergic rash. I've skinny-dipped in poison ivy-infested areas and trudged chest-deep in sumac-infested bog waters and have never gotten a rash. Knock on wood!!!