The Persian Ironwood of Artis

Artis keeps more than eight hundred trees across two hundred species, and the man who looks after them picks this one. Jan de Jong, the park's tree specialist, calls the Persian ironwood his favourite and describes it as warrig en grillig, tangled and irregular, which undersells it. The species does something few trees do: branches that touch as they grow fuse into each other, so an old ironwood ends up as one knotted structure rather than a trunk with limbs hanging off it. The bark flakes away in plates like a plane tree's, leaving patches of grey, green and brown. Amsterdam's register of protected trees carries it as N1763, planted in 1910, trunk 205 centimetres around. That makes it barely a century old, young next to the oak thirty metres away, which took root around 1750 and is the oldest tree in the city. The two are an easy walk apart, past the giant tortoises, and together they explain what Artis is: a zoo laid out in 1838 by a society that collected plants as seriously as animals, with the trees part of the plan rather than scenery added afterwards. In late autumn this one carries red, orange and purple in the same crown at the same time. Entry is a zoo ticket.