The Pecan of the Botanic Garden

The regional register calls this tree an American walnut, and that is close but not quite right. Carya illinoinensis is a pecan, in the same family as the true walnuts but a different genus, native to the river valleys of the American South. The garden's own catalogue lists it under three names at once, pacana, pecan and nogal americano, and places it in both the Bosque and the Escola Botanica collections. It is already a serious tree: 32.9 metres tall on a trunk 3.88 metres round, with a crown 16.1 metres across, large enough to earn its own entry in the region's monumental tree register. And yet the garden's own catalogue puts the species' full mature height nearer 50 metres in its native range, which means this specimen, whatever its age, still has real growing left to do. No planting record survives for it. The register measures the trunk and stops there; the garden's catalogue confirms the species grows in this collection but describes it in general rather than naming this individual tree by a date. It stands in the Bosque, a short walk from the Plane Tree, taller than that tree but carrying a far narrower crown, 16.1 metres against the Plane's 26.