Mary Agnes Chase, Clarissa Rolfs and Group on Expedition in Brazil, by Unknown, 1929, Smithsonian Archives - History Div, Mary Agnes Chase (third from right with the big hat) on a horse with Clarissa Rolfs, daughter of Peter Henry Rolfs of the Esculea Superior de Agricultura e Veterinaria do Estado de Minas Geraes, Brazil, second from left, and others on expedition in Brazil. Chase, a botanist with the United States National Museum and honorary curator of grasses at the United States National Herbarium at the Smithsonian Institution, specialized in the study of grasses and conducted extensive field work in South America..