Born on the 19th March 1903 in Capmprodón, Catalonia, Spain, the eldest son of a pharmacist, José Cuatrecasas would accompany his father on trips to collect plants for the family business. In 1923 he too attained his 'licentura' in pharmacy from the University of Barcelona and later his doctorate from the University of Madrid. He wrote his thesis, 'Flora y Vegetación del Macizo de Mágina', whilst simultaneously studying phytogeography in Geneva. In 1930 he began post doctoral studies at the Botanical Institute of Berlin-Dahlem, where he met his wife, Martha Nowack, and had three children.

In 1932 Cuatrecasas was to realise his calling in life, when sent to Colombia as Spain's representative on the bicentenary of José Celestino Mutis, taking part in his first expedition to the Páramo in the Cordillera Central. Athough he returned to Madrid to be curator and then director of the Real Jardín Botánico, his lifelong passion would remain the study of the montane forests and alti-platos of Colombia. He returned in 1938, conducting field trips to the Cordillera Oriental and the Llanos Orientales.

Cuatrecasas had began a publication about Mutis's Flora Americana, however it had to be abandoned due to the Spanish Civil War and when Franco took control of the country Cuatrecasas was forced to go into exile. He fled to Paris and awaited his family. In 1939 by invitation of the president Eduardo Santos they moved to Bogotá where he became a professor at the Botanical Institute of the National University and made considerable contributions to the National Herbarium. In 1942 he worked in Cali and founded the School of Agriculture here. Throughout his six years in Colombia he carried out extensive exploration of the forests between the Cordillera Occidental and the Chocó.

In 1947 he moved to Chicago to take up the role of curator of Colombian botany at the Field Museum of Natural History, between 1951-52 he was a Guggenhiem fellow before becoming a researcher at the National Science Foundation of the same museum. While here he studied and classified the large backlog of collections made in his expeditions in Colombia. He was later appointed research associate at the Smithsonian Institute and moved to Washington, DC, where he remained for the rest of his life. While based here he would make10 separate trips to Colombia and occasionally Venezuela (although he collected in a variety of countries, 95 per cent of his 28,553 collections from the New World were from Colombia). He produced hundreds of publications in his lifetime and was the author of a great many taxa. His passion was always the Asteraceae, especially the genus Espeletia. 'Don José', as he was affectionately known, has eight genera and 160 species named after him. The very idea of creating a Flora Neotropica was his and he was its first scientific director and its president from 1972-1975. One of the leading tropical botanists of the 20th century, when asked what he believed was the meaning of life, he replied 'Why it is the study of Botany'.