"Herbier Forestier de la France" was produced by De Gayffier in 1868 – 1873. This is one of the few books published that state[s] clearly that the plates are by the very rare Motay and Maréchal process. Motay and Maréchal are considered the first to have devised a practical implementation of the collotype process in 1865 and therefore it is one of the first books illustrated with collotypes rather than photolithography or photogravure. (Eder p. 617) The project was also noteworthy because it was one of the first instances to actually photograph true forest foliage and to document it, rather than the large parks near Paris, such as the Bois de Bologne. De Gayffier had been appointed by the Minister of Agriculture to its "special photographic operations" in 1867.
Hanson, David Checklist of photomechanical processes and printing 1825-1910, 2017 p. 133
Eder, Josef M, and Edward Epstean. History of Photography, by Josef Maria Eder. Translated by Edward Epstean. New York: Columbia University Press, 1945. Print.