Van Gogh expert sheds new light on lost sunflower paintings

One day in Arles in August 1888, Van Gogh was planning to paint from life. But the models he had hired failed to show up, and a harsh, hot mistral was blowing, making conditions for painting outdoors unbearable.
So he improvised: he took bunches of Provençal sunflowers, then at their golden-blooming best, and arranged them in locally made, half-glazed earthenware pots. He started work on Monday morning and by Saturday he had made four sunflower pictures.
Two of these are now among the most beloved, celebrated and valuable paintings in the world: they hang in Munich and in the National Gallery, London. Two are lost to public view – one was destroyed in an American bombing raid on Japan during the second world war, the other vanished into private hands after it was exhibited in Ohio in 1948.