The "El Peruano" had arrived in Cádiz on February 21, 1785, carrying part of the scientific material sent back from Peru and Chile by the royal expedition under Hipólito Ruiz and José Antonio Pavón. Also arriving on the "El Peruano" was Joseph Dombey, a Frenchman who had served as second botanist on the Ruiz and Pavón expedition. Cuéllar was to catalogue and sort the material and prepare it for transfer to the Casa de Contratación. Dombey, however, wanted to transship the specimens to France rather than opening the boxes in Spain. This conflict was resolved, however, and on August 17, 1785 the specimens were delivered to the Casa de Contratación. It may be because of this work that Ruiz and Pavón named the genus "Cuellaria" for him.