The Hackberry of National Grove

Of the three hackberries at the top of the Forest Preserves of Cook County's champion register, this one has the widest crown: about 23.5 metres one way and 21.6 the other, measured in December 2023. The register places it third among all the hackberries on preserve land. Its trunk is 3.51 metres round, exactly the girth of the county champion at Thatcher Woods, about seven kilometres to the north. What separates them is height. The champion stands 36.6 metres, this tree 34.1, and the second-ranked hackberry at Thatcher Woods reaches 39. Three trees of one species, within 16 centimetres of each other in girth and all past 34 metres tall: Cook County grows hackberries big. The gap with the rest of our map is wider. The only other hackberry of this species we have measured, the Leaning Hackberry of Parco Treves in Padua, is 1.55 metres round and 9 metres tall. National Grove's tree is nearly four times as tall, and its crown spans more than two and a half times the Padua tree's whole height. Unlike the Thatcher pair, it has no ranked neighbour on our map. It is a stop of its own. The register records size, rank and site, and no age. Nobody has dated this hackberry. If you know how old it is, tell us.