Great Works: Large Poppies, by Emil Nolde

Leopold-Hoesch-Museum, Düren

Flowers can be pugnacious presences. They catch you unawares. They can set the teeth on edge at the breakfast table. If you were to have made such outrageous remarks as these to Claude Monet, he might well have begged to differ. What is more, the notion that flowers might be violent presences seems to be slightly at odds with the idea of garden-making, which is much about the taming and the prettifying of nature by humankind.

Think of Monet again, for example. Monet was in the business of making and organising gardens – think of his great garden at Giverny, for example – and he often seemed to be quite pleased not only to control the way that flowers worked upon us, but then to show us the pleasing fruits of that control in his paintings. He was in the business of engineering very particular aesthetic effects. Flowers often seemed to be dancing to his tune.

Not so Emil Nolde, in a painting which dates from some way through his long career. Nolde had not contrived this garden for painting's sake, he happened upon it as a subject quite by chance. The subject seized hold of him. It led him on to new and ever more colourfully energised imaginative elsewheres. It helped to lever open the doors of perception.

Nolde has often been described as a German Expressionist, and this painting seems to encapsulate, to a degree, the spirit of Expressionism. It possesses an extraordinary subjective vigour, a very particular angle of attack. Unlike Impressionism, Expressionism does not soothe or narcotise us. It does not lull us to sleep. We never coo over it. It is often a brutal wake-up call, a mosquito in the inner ear. This is one of the reasons why Hitler and his nasty bullies didn't like it – or other equally dangerous manifestations of the individual spirit. Subjective violence of this kind was a great threat to National Socialism. At a stroke, it threatened to put paid to their bloody version of harmoniousness. This is why Nolde, in 1941, was charged with degeneracy and forbidden to paint. How did he respond? He began to make very small paintings, in secret, tiny watercolours which he called "unpainted pictures".

In this painting, the flowers seem like they might punch out our eyes. These ranks of poppies, deliciously bloodily smeary, seem to be approaching us, almost increasing in size as they do so, sweeping in from the left in great massings, faces tilted upwards to buttonhole our gaze, like ranks of determined soldiery. They will forever be in movement, we feel. Notice that it is a diagonal movement we are witnessing, and that very trajectory seems to increase and bulk out, the size of the space at which we are looking. To a degree, our sense of being under threat is magnified by the low angle of view.

This is in fact a small garden on an island, but it does not feel small. We have no real notion of its size, although it also feels large because it seems to contain such clamour, such a riot of energy. Its very hectic indefinition causes it to expand in size as we endeavour to make some sense of its shape, its proportions, its features. Surely we are not seeing it in its entirety at all – this is a mere corner, albeit a colourfully noisy one. We can never know for sure. All we experience is some overwhelming sense that it is in the throes of engulfing us.

There are motifs here – a stuttery, ochreous path down the left, for example, or that female form just about rendered in radiant yellows, whites and smearings of pink, which happens to be Nolde's wife – but they are always sketchy ones. They are designed to do little more than prove to us that we are somewhere rather than nowhere. Some painters begin and end with botany. Having lovingly observed, they then strive, just as lovingly, to replicate. The extraordinary intricacies of nature are more than enough for them.

With Emil Nolde, it was quite otherwise: nature seized him by the throat. It was an overwhelmingly radiant and totally unignorable presence. These flowers said to him: this is your subject. It was only much later – at least a decade on from this painting – that he started to take an interest in the wondrous minutiae of botany.

About the artist: Emil Nolde (1867-1956)

Although Emil Nolde learnt much from the masters of Impressionism, and later came to be regarded as an important figure in the German Expressionist movement, he was reluctant to commit himself to groups. His paintings often feel solitary – we find ourselves peering at strange mythological beings of the artist's own invention, whose impulses seem to antedate those of humans. Colours engulfed his palette, so much so that it would be easy to buttonhole him as "rhapsodic".