The Katsura of Mellon Park

In autumn, a katsura smells of burnt sugar. As the leaves yellow and fall they release maltol, the compound behind the smell of caramel and candy floss, and for a couple of weeks the ground under the tree smells sweet enough that people stop walking and look around for a bakery. That is the sort of thing Pittsburgh's Shade Tree Commission had in mind when it put this one on the city's first list of Remarkable Trees in March 2023, under the heading Tree of a Kind: not the biggest of its species, but unusual in form, origin or appearance. The list came from 44 nominations sent in by residents, of which 15 met the criteria. Three of those stand in Mellon Park, the city's first public arboretum, and this katsura is a short walk from the champion bald cypress at the Fifth Avenue and Beechwood Boulevard corner. Cercidiphyllum japonicum is Japanese, and it grows nothing like the oaks and maples around it. The leaves are small blue-green hearts set in opposite pairs, and the branches layer outward rather than climbing, so the whole tree reads as horizontal. In October the leaves go apricot and pale gold before they drop. No age, height or girth is on public record for it, which is true of all three Mellon Park trees on the city's list. Go in October and let your nose find it before your eyes do.