ART / Georgia on her mind: The paintings of the pioneering Georgia O'Keeffe, on show at the Hayward, betray the drawbacks of working in heroic isolation

SHE HAS long been regarded as a heroine of American culture, but Georgia O'Keeffe's retrospective at the Hayward reveals an artist at some distance from the first rank. Socially she was a pioneer, a woman who demanded equal terms. 'The men liked to put me down as the best woman painter. I think I'm one of the best painters.' But in truth her canvases are timid. Her pictures too often look like preparations for a better work that's just around the corner. But that corner is never turned.

Certainly she challenged the male painters of her time. The question now raised is whether she sufficiently challenged herself. There's a famous story of how in 1915, at the age of 28, she arranged all her work in her room to see how it stood up. Disappointed, she then destroyed everything she had made. It seems that she found her paintings too derivative. Indebted both to exercises (O'Keeffe had spent a long time both as a student and a teacher) and to Japanese art, the charcoal drawings that followed are original. They dare to use abstract motifs and have a haughty personal tone.

Henceforth, O'Keeffe would always insist on her individuality, therefore on the irrelevance of encouragement or criticism. All she needed was support, and this was supplied by the success of the charcoal drawings. They were exhibited by the photographer and entrepreneur Alfred Stieglitz, who showed them at his 291 Gallery in New York, rescued O'Keeffe from her life as a teacher, photographed her, married her, and organised all the exhibitions that were to make her a celebrated artist.

Stieglitz's photographs, although they doubtless contributed to her sudden fame, are not exhibited at the Hayward. It's O'Keeffe's show, and we are given only her work. This is upsetting, not only because O'Keeffe repeatedly fails to make a convincing picture, but also because her pictures look so lonely. It's not the emptiness of the New Mexico landscape that gives this impression, nor the absence of the figure, nor the solitary attention that O'Keeffe accords to her deserts, picked-up white bones and rare prairie flowers - her paintings are lonely because she doesn't love them enough.

The Hayward exhibition suggests that she was at her best as a watercolourist, and that she used the medium to best effect in the two or three years before 1920. Here are some of the most satisfying works in the show, small sheets like the Evening Star of 1917 and the various versions of Pink and Green Mountains from the same year. They can be counted among the first significant products of transatlantic abstract art.

Alas, the pungent colour in these watercolours was not developed. There are two sides to O'Keeffe's palette. On one hand it was formed by the camera, an instrument that could not possibly - especially in the 1920s - give instruction to a painter who wished to use hues for their own sake. On the other hand she heightened her colour by imitating the strange, strong light of the South-western desert states, with their red mountains and lurid dawns. The results are uneasy. As sometimes happens, fidelity to nature led to unnatural art. Photographic chiaroscuro helped O'Keeffe to relax. Far better than her fruits and flowers are the muted landscapes in which we see, characteristically, barns and outhouses under snow.

At the end of the 1920s O'Keeffe did a number of paintings of skyscrapers, a subject common among artists with a relish for New York. The theme obviously suited modernists who tended towards abstraction. In O'Keeffe's version, however, the influences don't come from European abstract art or from other American painters. Her skyscrapers are inspired by the movies and by the commercial art that advertised them. The results are not exactly accomplished, but they have life. One feels an eagerness in the painting, a desire to be part of the immediate urban scene.

This is an unusual sentiment in O'Keeffe. In both art and life she preferred separation. She was apart from Stieglitz, her only real influence, for long periods. She had little interest in art that was not her own and felt no comradely spirit for other painters. Her preference for isolation is often praised, but it had obvious drawbacks. The first of them was that she lacked criticism. Nobody told her when her paintings were going wrong, or suggested ways in which they might be improved. A sadness of this exhibition is the way that the artist seems content with her many failed paintings. And I do mean many: only a small handful of her pictures stands up to scrutiny.

Hayward Gallery (071-921 8800) to 27 June.

(Photograph omitted)