Born at Chandernagor in the East Indies, he spent his adolescense in Italy, where he completed his studies in natural science, concentrating especially on botany. Assistant to the famous botanist Filippo Parlatore (1816-1877) in Florence, he contributed to the realisation of the Central Italian Herbarium. Professor of Botany at the Universities of Pavia, Milan and Pisa, he was appointed director of the Giardino dei Semplici in Florence in 1880, subsequent to the retirement of Odoardo Beccari (1843-1920), the successor to Parlatore. Caruel was one of the founders of the Italian Botanical Society and directed for over twenty years Nuovo Giornale Botanico Italiano [New Italian botanical journal], founded by Beccari in 1869. He wrote the Prodromo della Flora Toscana [Prodrome of Italian flora] (1860-1864), and completed the Flora italiana [Italian flora] by Filippo Parlatore. He died in Florence in 1898.