Marietta Hannon Rousseau, also known as Mariette Rousseau (1850–1926), was a Belgian mycologist and taxonomist specializing in cryptogamic plants and fungi. She published several works on fungi from 1879 to 1905 with Elisa Caroline Bommer, focusing primarily on Belgium.

Elise Caroline Bommer, née Destrée, was a Belgian botanist specialising in mycology, and was the wife of pteridologist and collector Jean-Édouard Bommer (1829–1895), who was professor of botany at University of Brussels in 1872. The standard author abbreviation E.Bommer is used to indicate this person as the author when citing a botanical name.