The Plane Tree of Gråbrødre Torv

This plane tree was already famous enough in 1995 to go into a book called Berømte danske træer, famous Danish trees. Its author, Qvistorff, measured the trunk at 3.90 metres round. When the Danish Tree Register taped it again in December 2013 it had reached 4.19 metres, which is what eighteen more years of steady growth on a healthy plane looks like. It stands in the open public square of Gråbrødre Torv, Greyfriars Square, in the old Latin Quarter, about seven minutes' walk from Nørreport and close to Strøget. The tree is 21 metres tall, recorded as living and healthy, and rated remarkable at regional level rather than merely municipal. The register keeps two entries for it, an older one carrying the 1995 figures and a newer one with the 2013 measurement, and they describe the same trunk. That makes it a tree you can watch grow on paper. Most old trees are measured once, if ever. This one has a reading from a book of famous trees and a second from a dendrologist with a tape eighteen years later, and the difference between them is thirty centimetres of trunk added in a square in the middle of the city. Nobody has recorded when it was planted, and the square's own long history is not a date for the tree. If you know when this plane went in, tell us.