Last chance to see the extraordinary works of this Swedish pioneer at London’s Serpentine Gallery. Her colour-drenched, swirling, enigmatic abstracts were created years before Kandinsky, Modrian and Malevich took the art world by storm and she was experimenting with automatic techniques decades before the dadaists. Yet her name is almost unknown. Get down to the Serpentine this week to find out why she is such an important – and overlooked – 20th century painter.