Margaret R.B. Levyns, born Michell, botanist and phytogeographer, was the daughter of John H. Michell and his wife Margaret P. Michell, born Brown. She attended Ellerslie Girls' High School in Sea Point, Cape Town, and passed the matriculation examination of the University of the Cape of Good Hope in 1907. Continuing her studies at the South African College, Cape Town, where she studied mathematics, geology, chemistry and botany, she was awarded the BA degree with honours in botany by the University of the Cape of Good Hope in 1911. The next year she was awarded the college's 1851 Exhibition Science Research Scholarship and published her first paper, 'On the comparative anatomy of the genera Ceraria and Portulacaria' (Annals of Botany, 1912). Later that year she continued her studies at Newnham College, Cambridge, returning in June 1914. In November that year she was appointed for special research work in botany at the South African College, but had meanwhile returned to England on a scholarship for further studies in genetics and horticulture at the John Innes Institute. In November 1915, following the outbreak of World War I (1914-1918), she suspended her scholarship to work in a munitions factory, but returned to Cape Town in 1916 for reasons of ill health and was appointed as an assistant in the Department of Botany at the South African College under Miss E.L. Stephens*. She remained at the college (from 1918 the University of Cape Town), from 1919 as a lecturer in botany, until her compulsory retirement at the age of 55, at end of 1945. In 1923 she married John E.P. Levyns, but they had no children. In 1933 she became the first woman to receive the degree Doctor of Science (DSc) at the University of Cape Town, for her thesis A taxonomic study of Lobostemon and Echiostachys, gen. nov., based on their morphology, cytology and geographical distribution. Her 'Revision of the genus Lobostemon' was published in the Journal of the Linnean Society (Botany) in 1934.
After her retirement she was appointed honorary reader in plant taxonomy and continued her research in the Department of Botany and in the university's Bolus Herbarium. However, she soon resumed her lecturing duties for a while to help with the increased number of students that entered the university after the conclusion of World War II (1939-1945). She was an excellent lecturer and a kind person, retiring and humble, but also a plant collector and an outstanding researcher. In all she collected nearly 12 000 plant specimens during the period 1920 to 1970, mainly in the Western Cape and often jointly with her husband. Many of these are in the Bolus Herbarium. In 1958, after her husband retired, they undertook an extensive tour in Australia, as she wished to see the Gondwana connections between the Australian and southern African floras. Her publications dealt mainly with the taxonomy and phytogeography of the Cape flora, on which she was regarded as an authority. Perhaps her most important contribution was her pioneering Guide to the flora of the Cape Peninsula (1929, 2nd ed., 1966). She was also a major contributor to The flora of the Cape Peninsula (1950), edited by R.S. Adamson and T.M. Salter, in which she described thirteen families, including 43 new species. Some of her larger monographs dealt with the genera Elytropapus (1935) and Stoebe (1936), both of the family Compositae, and Muraltia (1954, family Polygalaceae), all of which were published in the Journal of South African Botany. A number of her other botanical papers were published in the South African Journal of Science and the Transactions of the Royal Society of South Africa. Some of these dealt with the effects of bush fires on the vegetation of Signal Hill (1922) and the Cape Peninsula (1924), the sea-weeds of the Cape Peninsula (1924), the troublesome renosterbos (1927, 1929), and veld-burning experiments near Stellenbosch (1929) and Riversdale (1936).
Levyns also played an important role in bringing botanical knowledge to the public. For example, she contributed numerous articles to the Standard Encyclopaedia of Southern Africa (1970-1976) and the Afrikaanse kinderensiklopedie (1944-1945). She was elected a Fellow of the Royal Society of South Africa in 1922 and served as its president in 1962/3. As a member of the South African Association for the Advancement of Science she served as president of its Section C (which included botany) at its annual congress held in Cape Town in 1924, and in 1958 was awarded the association's South Africa Medal (gold). She served on the council of the Botanical Society of South Africa from 1948 to 1958 and was elected an honorary member in 1965. Volume 34 (1968) of the Journal of South African Botany was dedicated to her. The plants that were named in her honour included Nivenia levynsiae, Crassula levynsiae and Thamnochortus levynsiae. After her death her husband donated her personal papers to the libraries of the University of Cape Town.