EXCLUSIVE: Juliette Lewis is in negotiations to join August: Osage County. The actress would play the role of Karen, the self-deluding youngest daughter, in the dark family comedy being financed and distributed by The Weinstein Company. Meryl Streep and Julia Roberts have already been cast in the film. Based on Tracy Letts’ Pulitzer- and Tony-winning play, August: Osage County tells the tale of a severely dysfunctional Oklahoma clan and the family crisis that brings them back together. John Wells is directing; Letts is writing the adaptation of his play. George Clooney and Grant Heslov are producing along with Jean Doumanian and Steve Traxler. Claire Rudnick Polstein is executive producing. The movie is scheduled to start filming in September. Lewis is repped by Buchwald/Fortitude and managed by Untitled Entertainment.