The Lehmann Plane of Planten un Blomen

Most old trees are dated by argument. This one has a date: 6 November 1821, when Professor Johann Georg Christian Lehmann put it in the ground as the first tree of Hamburg's new botanical garden, which he had founded and would direct. That makes it about 205 years old, and it is one of the few trees in this city whose age needs no tolerance attached to it. The garden it was planted to open has since moved on and the ground around it has become Planten un Blomen, a public park in the old ramparts on the edge of the centre. The plane stayed put and kept growing: 29 metres tall and 6.15 metres round when it was measured on 1 November 2020, with a trunk that leans slightly out of true and throws its first branch off low and steeply, at about three metres. Hamburgers call it the Lehmann-Platane. The botanical garden's own history describes it as its living founding document, which is unusually good phrasing for an institution writing about itself, and accurate: the garden was founded around this planting, and the planting is still standing, free to walk up to.