Caucasian Wingnut

The Caucasian wingnut is a walnut relative from the humid forests between the Black and Caspian Seas, and Amsterdam has more remarkable ones than almost any city outside its native range. It reached Europe around 1782 and thrives in exactly the wet, soft ground that much of the Dutch capital is built on. In summer it hangs curtains of green winged seeds, the catkins that give it its name, sometimes half a metre long. Left alone it suckers into a small grove from a single tree, which is why several of the city's specimens read as thickets rather than trunks. Amsterdammers have gone to court to keep them: one felling permit fight over a pair of wingnuts ran all the way to the Raad van State, the country's highest administrative court. These are the wingnuts mapped on the site so far.