Finally opening after months of delay and a last-minute pull from theaters, Leaves of Grass is an ambitiously high-falutin’ pot-head laffer—which is not to say it’s in any way outrageous, visionary, or even particularly funny. The most notable thing about Tim Blake Nelson’s movie is its stunt casting. Edward Norton plays twins—identical and equally improbable: Billy Kincaid is a straight-arrow Ivy League classics prof who transcended his dirt-farmer roots, while laidback brother Brady stayed put to become the down-home king of hydroponically farmed cannabis sativa. Brady, of course, is just as brilliant as Billy, and a lot craftier—stuck in a jam, he cleverly lures his estranged brother back to Oklahoma to unwittingly provide him with a physical alibi while he sorts out his messy business with a drug lord in Tulsa. Norton is fully capable of shouldering the movie’s comic burden, although Nelson surrounds him with a gaggle of hambone performances. The liveliest cameo is provided by Richard Dreyfuss as the toughest Jew in Tulsa, who at one point wields a menorah in self-defense. With its comic regionalism and ethnic stereotypes, sudden shifts in tone and cultivated eccentricity, farcical violence and escalating body count, Leaves of Grass is highly evocative of another brother act, namely Joel and Ethan Coen. Unfortunately, Nelson is not nearly so gifted a filmmaker. I don’t much care for the Coens, but the sad truth is that their cynical nihilism is a lot less spurious than Nelson’s earnest sentimentality.