The Critics: Exhibitions - Sometimes, Suprematism begins at home

If there are three words guaranteed to strike dread into an art critic's heart, they are "lost genius" and "reclaimed". The first two are favoured by historians and curators keen to bolster their reputations by rediscovering those of forgotten artists. The trouble is that history does not often misplace genius: it overlooks mediocrity. Of these rediscovered geniuses, a disproportionate number are women who have recently been "reclaimed" - the term used by feminist art historians - from the injustices of a male-dominated past. The problem here is one of emphasis. Yes, it is mildly heinous that the Caravaggist painter, Orazio Gentileschi, should be known by his surname while his talented (but overlooked) daughter is known as Artemisia Gentileschi. But to reverse this injustice - as reclamatory feminists do by referring to Artemisia as Gentileschi and her father as Orazio - is to compound it. To claim Artemisia as Orazio's equal is to lie.

All this means that you may approach the Henry Moore Institute's show of the work of Katarzyna Kobro with a certain trepidation. Kobro has certainly been lost to history. Born in Moscow in 1898, she was an early adherent of UNOVIS, the association of left-wing artists founded by Kasimir Malevich after the Russian Revolution. As a disciple of Malevich's, Kobro set up a UNOVIS branch of her own, and adopted his Suprematist beliefs. Broadly speaking, Suprematism took the geometric tendencies of Cubism to their abstract extreme by freeing painting from the need to portray anything but itself.

Where Kobro differs from her Suprematist mentor, though, is in the way in which history has treated them. While Malevich is remembered as a giant of early Russian experimentalism, Kobro has been pretty well forgotten. When her name is included in textbooks at all, it is usually as a footnote to the career of her hardly more talented husband, Wladyslaw Strzeminski. Since Kobro's career was supposedly curtailed by Strzeminski's ill treatment of her after their return to his native Poland - her wooden sculptures were burnt for heating, at his bidding, during the German occupation of Warsaw - the temptation for the Institute's curators to reclaim Kobro as a lost genius must have been immense.

Wisely, though, they resisted it. The Leeds show has no need of over- egging: the simple truth is that Kobro's work is extraordinary. Whatever his eventual role in her artistic career, Strzeminski was undoubtedly right when he wrote that Kobro's "Suprematist sculptures are a phenomenon on a European scale, a real step forward ... they are not an imitation of Malevich but a parallel creation". Comparisons may be odious, but Kobro's exploration of space seems less cerebral than Malevich's, more heartfelt.

Given this, her adoption of a Constructivist style in the mid-1920s is also understandable. Constructivism may have followed the formal tenets of Suprematism, but it was also a reaction against Malevich's intellectual airy-fairiness in favour of something more down to earth. In Kobro's case, this took the form of an increasingly architectural content in her sculpture. Look at the collection of Kobro's white curves and lines and you will see two things: abstract sculptures playing cerebral games with ideas of spatial enclosure, and architectural maquettes which deal with space in a way that is entirely domestic. Kobro's Spatial Composition 8 (1932) is not just a piece of sculptural abstraction but a tiny, white, Corbusian villa. This double impulse, to explore and to domesticate - the second, one suspects, unconscious - makes Kobro's work very beautiful to look at and (unusually in Modernism) curiously touching.

All the more so, perhaps, given its exclusion from the Barbican's show of Russian avant-garde art. Malevich is certainly there - indeed, he is credited as the exhibition's moving spirit - as are two works by Kobro's husband. Kobro's absence is not the result of an anti-feminist plot, however, so much as that the Petrograd Museum of Artistic Culture happened not to have her work in its collection. Put together between 1910-26 and hidden away in what is now the State Russian Museum during the long decades of Stalinist repression, this collection forms the basis of the show. Although a few of the works in it are familiar from reproductions, the collection itself has never been seen in its entirety outside of St Petersburg. Set up by the artists themselves as an antidote to the state art museum, the Museum of Artistic Culture embodied both the optimism and the dynamism of the revolutionary period in art. Its collection is quite literally breathtaking: exhausting, occasionally maddening, marvellous.

Is there a collective noun for isms? They are all in the Barbican's show: Impressionism, lapped up from the Shchukin and Morozov collections by Mikhail Larionov; Fauvism, lifted from the same source and Russianised by Olga Rozanova; Futurism in Goncharova's The Cyclist (1913); Post- Impressionism; Orphism; Primitivism; Cubism. By Room 4 you find yourself elated but slightly light-headed: this entire outpouring of artistic energy took place in a little under 18 years. Look at Boris Grigoriev's hard- edged study of Russian peasant life, Land of the People (1917-18), and you may even see the first stirrings of Socialist Realism, eventually to become the officially enforced state style and putting a brutal end to Malevich's avant-garde in the process.

At the same time as busily imbibing the latest artistic trends from Paris and Berlin, the stormtroopers of Malevich's avant-garde were inventing movements of their own, echoing Tolstoy's influence in literature by finding a voice which was both overtly Russian and covertly anti-Western. (They mined native folk art by exhibiting things like distaffs and painted tea-trays - included in this show - alongside works by Larionov and Goncharova.) And, being both Russians and artists, they were also perpetually arguing with each other: they even turned on Malevich himself. Rodchenko's 1918 riposte to Malevich's Suprematist manifesto series, White on White, is in the show: a study in material darkness, it is called, inevitably, Black on Black.

'Katarzyna Kobro': Henry Moore Institute, Leeds (0113 246 9469) to 27 June. 'New Art for a New Era': Barbican Art Gallery, EC2 (0171 638 4141), to 27 June.