Bertha Stoneman, botanist, was the daughter of Byron and Mary M. Stoneman and came from a prominent American family. She was a teacher for five years before entering Cornell University, New York, where she was awarded the degrees Bachelor of Philosophy (PhB, 1894) and Doctor of Science (DSc, 1896), the latter for her research on fungi. This work was published as "A comparative study of the development of some anthracnoses" in the Botanical Gazette (1898). She was a member of the Congregational Church with strong religious views and a desire to improve the education of women. Hence she came to the Cape Colony in 1897 to teach botany for a year at the newly founded Huguenot College for women (from 1916 the Huguenot University College), Wellington. However, she remained for the rest of her life and at various times also lectured on zoology, psychology and logic. On the basis of her doctorate from Cornell University the University of the Cape of Good Hope admitted her to its DSc degree in 1899. In 1921 she became principal of the Huguenot University College and gave up teaching botany. She never married, but was a kind and generous person who took an interest in the welfare of her students.
Stoneman collected plants in various parts of the Cape Province and in Lesotho. She built up the College herbarium, but published relatively little. Her Plants and their ways in South Africa (London, 1906, 283p), written at the request of the Cape Education Department, was a school textbook for many years and was expanded in a second and third edition. As co-author with Willem S. Logeman, professor of modern languages at the South African College, she compiled a Glossary of botanical terms: Dutch-English and English-Dutch (Cape Town, 1920, 2 vols).
Stoneman became a member of the British Association for the Advancement of Science in 1905, when it held its annual meeting in South Africa. That same year she became a life member of the South African Association for the Advancement of Science and in 1914 read a paper at its annual congress on "Some observations of synaesthesia" (the psychological phenomenon that stimulation of one sense may produce sensations in another sense, for example, "hearing" colours). The paper was published in the association's Report for that year. In 1923 she served as president of Section C (which included botany). Her presidential address dealt with "The search for crucial instances in botanical procedure". By 1920 she was a member of the South African Biological Society. In 1923 she became the first president of the South African Association of Univeristy Women. She was an active member of the Huguenot Missionary Society, national representative of the Woman's Christian Association of South Africa, and for some time president of the Convocation of the University of South Africa. In 1937 she published A book of verse.
Stoneman retired in 1933. She intended to settle in the United States, but returned to South Africa after a short visit. In 1941 she built a house named "Stonemansion" at Bain's Kloof, where she lived until her death. The property was then given to the Botany Department of the University of Cape Town as a fieldwork research centre. Out of a bequest of hers the South African Association of University Women created the Bertha Stoneman Fellowship for Botanical Research in her memory.