Brazilian-Portuguese botanist and Franciscan monk. José Mariano da Conceição Velloso was born in São José del Rei (Minas Gerais) and was dedicated to the study of natural history from a young age. Velloso's religious virtues were well known and he became a Franciscan monk in the monastery of Boaventura in Macacú in 1761. The following year, at just 19 years of age, he became a teacher in the monastery of Santo António in Río de Janeiro and in 1766 was named confessor at the same establishment. Later Velloso became a professor of geometry and rhetoric in the monastery of São Paulo where he was also the confessor.

At this time he began to develop a growing interest in botany and founded a museum of natural history and a herbarium in the monastery. Velloso displayed such talent as a naturalist that the Viceroy of Brazil, Luis de Vasconcellos y Soussa, requested from his superiors that he be allowed to take part in exploratory excursions throughout the country, which he was granted and he undertook numerous collecting trips throughout the country. In 1790 he travelled to Portugal with the Viceroy and worked in the museum, garden and science academy of Lisbon, organising and classifying the specimens from his excursions in Brazil. From this work Velloso created the famous 11 volume Flora fluminensis, containing the images of 1,640 species from around Rio de Janeiro which would not be published until after his death, with intervention and revision by Antônio de Arrabida and João da Silveira Caldeira (director of the National Museum of Rio de Janeiro). The publication of three quarters of the text occurred in 1825 and the plates were published between 1827 and 1831, but the complete work was not published until 1881 by Ladislau de Souza Mello-Netto. The original manuscripts for this work are housed in the National Library in Rio de Janeiro.

While in Portugal Velloso also directed the Office of Typography, which had been founded in 1799, before returning to Brazil in 1808. He published other works on halophytic plants, quinine in Brazil, some notes on cloves and pepper and a book of instructions on how to be a naturalist; he also created a gallery of Brazilian birds. His cousin, Joaquim José da Silva Xavier, is also known for his participation in Brazil's struggle for independence.

Sources:
Colmiero, M., 1858, La Botánica y Los Botánicos de la Península Hispano-Lusitana. Imprenta y Estereotipia de M. Rivadeneyra. Madrid.
Carauta, J. P. P., 1973, "The text of Vellozo's Flora Fluminensis and Its Effective Date of Publication", Taxon 22(2/3): 281-284
García Montoya, F., 2003, Botánicos de los Siglos XVI, XVII y XVIII. Cabra. Córdoba.
Reis, F., 2003, José Mariano da Conceição Veloso (1742-1811). Instituto Camões: http://cvc.instituto-camoes.pt/ciencia/p16.html.