"Why speak when you can paint?" asks Georgia O'Keeffe (Kathleen Chalfant) at the start of a one-woman show about the celebrated artist at George Mason University's Black Box Theatre. Good question, Georgia. Like so many other theatrical vehicles that attempt to capture the essence of a famous man or woman, Constance Congdon's "A Conversation With Georgia O'Keeffe" treats its subject with great respect, and entirely from her perspective. That approach certainly makes for ennobling biography and lively anecdotes, but very little in the way of gripping, revelatory drama.

When we first meet O'Keeffe, she is standing with her back to us in silhouette, facing a blowup of one her landscapes of mountain and sky. She then comes to life as a flinty gal of approximately 70, dressed in a monochromatic outfit of brown skirt, jacket and wide-brimmed hat, walking ramrod straight across her sparsely appointed studio (which we assume to be her digs at Ghost Ranch outside Santa Fe, N.M.). A mission-style chair and table stand to one side, the latter covered with a beautiful glass pitcher, a bleached animal skull and other resonant artifacts.

Despite the reference to "conversation" in the show's title, O'Keeffe is not one to sit back and schmooze. Thoroughly no-nonsense, she has to be doing something while regaling us with stories about her childhood on a dairy farm in Wisconsin, her days at New York's Art Students League, her first encounters with the great love of her life, photographer Alfred Stieglitz, and her fascination with the light and space of the Southwestern United States. Congdon -- whose prize-winning "Tales of the Lost Formicans" played to much acclaim here last season at the Woolly Mammoth -- has enough sense to avoid showing us the artist at work on one of her masterpieces. Instead, she sets O'Keeffe on her hands and knees, painting a simple wooden chair "antique white" -- an activity that proves neither distracting nor artificial.

During the course of this intermissionless 80-minute monologue, we're offered both a chronological survey of O'Keeffe's life and an ample dose of her thoughts on men, women, nature, critics and other salient topics. Working in cooperation with the artist's estate, Congdon appears to have used all manner of letters, documents and other sources -- many of them oft-quoted -- to construct her text.

We hear about the painter's earliest memory of the shape made by buggy tracks in the dust. She muses over her days in Manhattan, her introduction to the drawings of "Ro-dan" and other wonders at Stieglitz's ground-breaking gallery 291. She portrays herself as a spunky suffragist, a member of the National Women's Party. Yet she hates being referred to as a "woman artist," bad-mouths all the women in her immediate family and declares that if men helped her very little, women helped her not at all. She also scoffs at the suggestion that there might be any sexual references in her renditions of irises and calla lilies (she chortles about a lady who, after hearing that a friend had one of O'Keeffe's flower paintings rehung, remarked: "I'm so glad you took down that vagina"). Is it denial? Repression? Congdon never lets us find out.

The playwright does make sure to have O'Keeffe fill us in on eccentric characters such as socialite Mabel Dodge Luhan, D.H. and Frieda Lawrence, and other members of the artsy clan that hung out at Ghost Ranch. Yet by allowing her subject to call all the shots, Congdon never really plumbs the depths of the painter's soul. O'Keeffe alludes to the fact that she wanted a child -- Stieglitz encouraged her to abandon that notion and to focus on her art -- but the subject is quickly dropped. We hear about her gradual estrangement from him, but nothing about the younger model and budding photographer who became her rival for Stieglitz's attention. And we learn nothing about Juan Hamilton, the handyman-potter who met O'Keeffe in 1972 and became a major player in both her personal and professional lives.

In spite of the play's shortcomings, Chalfant's performance is masterly indeed. With her hair scraped back and her head held high, she looks uncannily like the severely beautiful O'Keeffe. Her steely gaze and measured gestures speak of a woman who has very particular ways. And the manner in which she cherishes both speech and silence makes one vibrantly aware of that mix of grandeur and loneliness that formed the artist's existence. This is acting at once lush and spare -- rather like O'Keeffe's finest canvases.

A Conversation With Georgia O'Keeffe, by Constance Congdon. Directed by Greg Leaming. Set and lighting, Daniel MacLean Wagner; costumes, Lynnie Raybuck. With Kathleen Chalfant. A Theatre of the First Amendment production. At George Mason University's Black Box Theatre through Feb. 17.