Last time American audiences saw Charlotte Gainsbourg, she was hacking away at her husband's genitals in Lars von Trier's Antichrist. She's not quite as deranged in her new film, French director Julie Bertuccelli's innocuous, rather silly Australia-set drama The Tree, but all things are relative; she does snuggle in bed with a giant branch at one point, and later gazes up at the Moreton Bay fig of the title and murmurs, "Talk to me." Terrence Malick can pull that kind of thing off, but Bertuccelli is no Malick.

In the film, adapted from a novel by Judy Pascoe, Gainsbourg plays Dawn, a recent widow left to raise her four children on a dusty farm near Brisbane. One of her brood, 8-year-old Simone (the impressive Morgana Davies), sets up house in a massive tree in the backyard, convinced that it's now hosting her father's spirit. Dawn goes along with the idea at first, but then balks when she strikes up a romance with the hunky local plumber (Marton Csokas). Will Dawn and her family cling to the tree, with its rapidly spreading roots and thrashing limbs, or will they cut it down and, you know, move on?

It's a flimsy premise for a feature-length film, and accompanied by a bittersweet piano score, lots of rustling nature sounds, light-filled landscape shots, and spare dialogue, the results are on the precious side. The Tree isn't exactly bad; Bertuccelli creates a vivid sense of place, and the whole thing goes down painlessly enough. But movies about the strange ways people mourn have become a tired genre, and this one, despite its eccentric, boldly obvious central metaphor, feels bland and oddly inconsequential. None of the people in the film, not even the stubborn little firecracker who insists on sleeping in the tree, have any jagged edges or angles; their emotions and behaviors seem predictable and neatly programmed from start to finish. The Tree is so numbingly gentle that we're relieved when it occasionally veers into weirder, more menacing territory—as when the kids try to flush frogs down the toilet or a bat all but attacks Dawn as she's sipping tea in the kitchen.

Alas, Bertuccelli always returns to the gargantuan botanical symbol that weighs down her movie and helps her serve up platitudes about life and death. "We've had it with this tree stuff!" one exasperated character exclaims toward the end. That about sums it up.