Elaine May tries her hand at many things in this, her first film. Not only does she write, direct, and co-star, but the material of the film is a mishmash of black comedy, verbal comedy routines derived from her past work with Mike Nichols, physical comedy centering on her own character, a riches-to-rags morality tale, culture clash comedy, class comedy, and more. Who knows what else was in May’s original three-hour cut of the movie, which I hear was drastically different from (and darker than) the studio-tinkered 105-minute version? But even as it is, May’s whole career is in this film: a brilliant writer and comedienne who was unable to prioritize her strengths.

May’s sporadic career since then has included a decent attempt to make a John Cassavetes film in Mikey and Nicky, which not only starred Cassavetes but used his uniquely inefficient directorial and improvisational methods. It’s a good movie, and I like it more than most Cassavetes flicks, but any trace of May’s past personalities are subsumed by seeming Cassavetes worship. She also helmed notorious disaster Ishtar, which I haven’t seen. Like her ex-partner in comedy Mike Nichols, she’s proved herself a capable hack on several occasions, script-doctoring decent Hollywood movies like Reds and Tootsie (as well as Labyrinth, inexplicably), and adapting Washington hack Joe Klein’s Primary Colors for the big screen.

A New Leaf stars Walter Matthau as a useless, decadent upper-class playboy who, after spending himself into the ground, decides he has no choice but to marry for money, then kill the wife, so that he doesn’t have to put up with her. He finds his match in Elaine May’s botanist heiress, a thoroughly oblivious, Clouseau-level klutz who falls hard for Matthau’s rather skillful romancing. Matthau himself is so antipathetic towards women as to be asexual, but is excellent at feigning interest when the stakes are financial ruin.

(As to why May incongruously cast herself and Matthau as two upper-class WASP gentiles, I can only chalk it up to instinct. Matthau has the harder task, but when it works, which is mostly, it works brilliantly.)

The first quarter of the film, before May’s heiress shows up, plays like a collection of leftover Nichols-May routines. They reassert the problem of Nichols and May, which is that toothless satire can be very funny, but calorically empty. (The two are positively genteel next to Beyond the Fringe and Woody Allen’s standup material.) May’s script makes a great catchphrase out of “There’s carbon on the valves,” but mostly it’s a warmup act. Then May shows up and the picture turns inside out. May’s flightiness and physical schtick is so impressive that it comes to dominate the whole film. Dry wit is left behind for inspired slapstick, something that’s always been in rare supply. Matthau is perfect as the foil once he has May’s hapless force of nature to reckon with, but May’s physical presence is overwhelming. Nothing before had revealed her abilities in this area, and not much has since. Her huge glasses are perpetually falling off her nose, she ties herself to a tree to unroot a fern tree on the side of a shore ledge, and she’s incapable of wearing clothing correctly.

May is as good as Peter Sellers or Jean Harlow, and she completely absolves the picture of its disjointedness and slow bits. She could have staked a claim as a screen comedienne as brilliant as Andrea Martin or Madeline Kahn, and in this movie she was.