The Green Ash of the Sot de l'Estany

This ash comes from the flooded river bottoms of eastern North America, a species built to have its roots underwater for weeks at a time, and it is rare enough in Barcelona that the city's own tree catalogue calls it out by name. Planted in 1924 in the same sheltered ravine, the Sot de l'Estany, that shelters the botanical garden's giant wingnut, it has grown past 24 metres tall on the humidity the old quarry pit traps at the bottom of Montjuic. Green ash rarely gets planted as an ornamental tree in Mediterranean Europe, where its native swampy habitat has no local equivalent, which is part of why the Catalan government granted it monumental status alongside three neighbours in April 2025: not the biggest tree in the garden, but among the least expected. Botanists visiting the garden's deepest corner can, in a few square metres, find a Chinese-Caucasian hybrid, an American swamp tree, a native Iberian ash and a European maple relative growing side by side, an unplanned arboretum inside an arboretum.