Margaret Ursula Brown was born in Whitehill, Chesham in 1909. She attended Dr Challoner’s Grammar School, Amersham, followed by The School of Art, Science and Commerce, Watford. After a short period of teaching in Liverpool she decided to travel abroad.

While in Berlin in 1933, Brown witnessed the burning of the Reichstag and subsequent Jewish boycott, which confirmed her left-wing views. During the Second World War she worked in Hatfield as a draughtswoman at the de Havilland aircraft factory.

Mee married Reginald Bruce Bartlett in January 1936. Like her husband, she became a committed trade union activist for the Union of Sign, Glass and Ticket Writers and joined the Communist Party. Mee addressed the TUC in 1937, proposing the raising of the school-leaving age and was subsequently offered, but declined, a job with Ernest Bevin. The marriage to Bartlett was not happy and, after a long separation, ended in divorce in 1943. She later married Greville Mee, who was also attending Saint Martin’s School of Art, in the late 1940s.

After the war Mee studied art at Saint Martin’s School of Art in London. In 1950 she attended the Camberwell School of Arts and Crafts, where she learnt her style of illustration, and received a national diploma in painting and design in 1950. She moved to Brazil with Greville Mee in 1952 to teach art in the British school of São Paulo. Her first expedition was in 1956 to Belém in the Amazon Basin. She then became a botanical artist for São Paulo’s Instituto de Botanica in 1958, exploring the rainforest and more specifically Amazonas state from 1964, painting the plants she saw, some new to science, as well as collecting some for later illustration. She created 400 folios of gouache illustrations, 40 sketchbooks, and 15 diaries.

Mee travelled to Washington D. C., USA in 1964 and briefly to England in 1968 for the exhibition and publication of her book, Flowers of the Brazilian Forests. She gave a lecture in Washington D. C., USA in 1967. She returned to Brazil and joined protests to draw international attention to the deforestation of the Amazon region.

In 1976 Mee was awarded the MBE for services to Brazilian botany and a fellowship of the Linnean Society in 1986. She also received recognition in Brazil including an honorary citizenship of Rio in 1975, the Brazilian order of Cruzeiro do Sul in 1979, In her honour, after her death the Margaret Mee Amazon Trust was founded to further education and research in Amazonian plant life and conservation, by providing scholarships for Brazilian botanical students and plant illustrators who wish to study in the United Kingdom or conduct field research in Brazil.

Mee died following a car crash in Seagrave, Leicestershire on 30 November 1988. She was 79. In January 1989 a memorial to her life, botanical work and environmental campaigning took place in Kew Gardens.

In 1990 Mee was recognised for her environmental achievements by The United Nations Environment Programme (UNEP) and added to its Global 500 Roll of Honour.

The Diaries of Margaret Mee, written between 1956 and 1988, were published posthumously in 2004 and included an illustrated account of Mee’s expeditions to the Amazonian rainforest. Most of her illustrations are now part of the Kew Gardens collection.

In July 2020 a virtual exhibition of 20 of her paintings from Amazon exhibitions was shown by the Dumbarton Oaks Research Library, Washington, USA. They had been acquired by Mildred Bliss in 1966 and 1967.