Last week, the Oakland Museum of California (1000 Oak St.) opened Altered State: Marijuana in California. The 3,700-square-foot exhibition, which took over a year and a half-million dollars to develop, is broken into informative and interactive sections addressing the historical, cultural, environmental, and political dimensions of cannabis at the state and local levels. That means Altered State includes, in what’s surely a first for the museum, live pot plants behind glass and stems and leaves for attendees to handle with biohazard gloves. But more to the point, Altered State’s illuminating and intuitively navigable installations leave attendees with the impression that the popular perception of pot throughout history has never really been about pot, but about prevalent attitudes regarding class, race, and commerce. And commerce feels especially urgent in the show, since Altered State anticipates what will likely be a state ballot measure to legalize recreational weed in November.