"Luminous", "haunting" and "electrifying" — what puny words to describe Janet McTeer, a British actress with the regal, imposing manner of Vanessa Redgrave and a lusty, rippling laugh that pulls you right into her corner. If you caught McTeer's 1997 Tony-winning performance on Broadway in A Doll's House, you saw an alchemist who could make high drama and rollicking comedy out of eating a macaroon.

Tumbleweeds lets McTeer shine on film. As Mary Jo Walker, a much-married Southern belle who only stays in one place long enough to find a man and dump him when the relationship turns abusive, McTeer is a force of nature. Her twelve-year-old daughter, Ava, beautifully played by Kimberly Brown, is swept away on Mom's manic energy. As the movie opens, they've left West Virginia for California and settled in a beach community near San Diego, where Ava struggles to put down roots while Mom finds a dead-end job and another Mr. Wrong (Gavin O'Connor.

O'Connor, who also directed the film and co-wrote the screenplay with his ex-wife, Angela Shelton (the story is based on her childhood history), has taken on a tired genre — the parent-child tear-jerker — that runs the gamut from Alice Doesn't Live Here Anymore to the current Anywhere but Here. But the quirky humor and blunt honesty of Tumbleweeds — a Sundance hit — pays emotional dividends when Ava stands her ground and Mary Jo develops a relationship with a man (the excellent Jay O. Sanders) that doesn't depend on sex. McTeer and Brown make magic in a film that is wonderfully funny, touching and vital.