The Italian installation explored the threads that connect humans to their natural environments, and how one architect’s awe in the face of nature led him to embark on an epic 20-year project to create a seminal design guide. While studying architecture in Florence in the early 1960s, Cesare Leonardi had been struck by the rich vegetation of the surrounding hills and the monumental trees in the city’s parks.

“I felt a greater attraction than I did for the forms of architecture,” he later recalled. He quickly realised that landscape designers had few resources detailing the structural elements that they used most in their work: trees. The books that existed were usually of a botanical nature, and of little use for design purposes.

In order to provide this missing tool, he and his studio partner Franca Stagi conducted a systematic 20-year study of trees, travelling the length and breadth of Italy, and eventually extending their research to other European countries and Central America. They photographed every exemplar that they believed to be representative of its species, before redrawing it at a 1:100 scale. Drawing was an interpretative process that rarely consisted of merely copying the photograph. The aim was always to summarise the characteristics of the tree – the size and shape of the trunk, the composition of the foliage. In the case of deciduous species, the tree was represented in two versions: with foliage and bare. Further illustrations showed the shadows of the trees over the course of a day and its colour over the changing seasons.

In 1982, Leonardi and Stagi finally published their labour of love. 'L'Architettura degli Alberi' comprised 374 drawings of 211 species and is still an indispensable aid for designers of parks and public spaces. Twenty-four of these drawings were presented by Triennale di Milano at London Design Biennale 2018.