Il Noce del Caucaso dei Giardini Montanelli

Milan has three Caucasian wingnuts worth crossing town for, and this is the widest of them: 5.5 metres around, against 4.7 in the Brera botanical garden and 4.35 for the better-known specimen leaning over the pond in Parco Sempione. The city's own arborists pair this tree with the Sempione one as the two oldest of their species in Milan, which is as close to a date as anyone has put on either. It is a squat, wide, low tree rather than a tall one, 20 metres at most, because Pterocarya fraxinifolia spends its growth on width and on suckers: left alone it throws up new shoots from the base until a single tree reads as a thicket. Ash-like compound leaves, sometimes 60 centimetres long, turn butter yellow in late October. The species arrived in European gardens from the Caucasus and northern Iran in the early 1780s, brought back by a French botanist who found it growing in the wet forests south of the Caspian, and Milan planted it in parks for the same reason it planted bald cypress: land near ornamental water needed trees that would not sulk with wet feet. Walk the gardens' western edge toward Via Manin and it is the broad, many-stemmed one nobody photographs.