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.

Henri François Pittier de Fabrega was a Swiss-born geographer and botanist who started Venezuelan National Park history.