 He undertook a botanising trip in the foothills of the Andes in 1875–76 that resulted in the introduction of numerous hardy and tender plants new to European cultivation; his researches resulted in a volume on bromeliads, "Bromeliaceae Andreanae.Description et Histoire des Bromeliacées récoltées dans la Colombie, l'Ecuador et la Venezuela," Librairie Agricole, Paris, 1889.His pupil and assistant, Charles or Carlos Thays went to Buenos Aires in 1889 and was responsible for the planning of tree-lined boulevards and public gardens, resulting in the French atmosphere often noted in that city.