Klas Robert Elias Fries

(Klas) Robert Elias Fries (11 July 1876, Uppsala – 29 January 1966, Stockholm), the youngest son of Theodor Magnus Fries (1832–1913) and grandson of Elias Magnus Fries (1794–1878) and an expert on mushrooms. A Swedish botanist who was a member of the British Mycological Society and involved with The Botanical Museum (UPS), Botanic Garden and Botanical Museum Berlin-Dahlem, Natural History Museum (BM), the National Botanic Garden of Belgium (BR), Conservatoire et Jardin botaniques de la Ville de Genève (G), Royal Botanic Gardens, Kew (K),the Swedish Museum of Natural History Department of Phanerogamic Botany (S) and the United States National Herbarium, Smithsonian Institution (US).

A collector of plants from 1901 through 1923 in Europe: Sweden; Tropical Africa: Kenya; Tropical South America: Bolivia; Temperate South America: Argentina. He sometimes worked with his father and his brother Thore Christian Elias Fries (1886–1931).