Inez Clare Verdoorn, botanist, was the daughter of a surveyor's draughtsman and his wife, who was a sister of the naturalist Eugène Marais*. She received her secondary schooling at the Pretoria High School for Girls and at the Loreto Convent, where she matriculated in 1916. During her matric year she joined a school visit to the Division of Botany and Plant Pathology, headed by Dr Illtyd Pole Evans*, and wrote up her impressions of the visit for inclusion in the school's letter of thanks. After matriculating she started work in the War Office of Transport and Remounts (this was during World War I, 1914-1918), but soon transferred to the Controller and Auditor General's office. However, when the post of herbarium assistant became vacant in the Division of Botany, Pole Evans managed to have her transferred to his staff. She started work there on 1 April 1919, her main duty being the pressing and mounting of plant specimens under the supervision of the curator, Miss Sydney Stent*. She soon developed an interest in botany and started to study the subject on her own, managing that same year to publish her first paper, "The genus Fagara, as represented in the South African herbaria" (Journal of Botany, 1919). This was soon followed by "The order Primulines as represented in the Transvaal" (South African Journal of Science, 1920) and several other papers during the next few years. In 1920 she started part time studies in botany, zoology and chemistry at the Transvaal University College, but she had difficulty coping with the extramural work in chemistry, partly as a result of ill-health, and Pole Evans advised her to give up her formal studies. She continued to study botany on her own with such success that in 1925 she was appointed as South African Scientific Liaison Officer at the Royal Botanic Gardens, Kew. She held this position until 1927, when she returned to the Division of Botany. In 1944 she was promoted to senior professional officer and put in charge of the National Herbarium, despite her lack of formal qualifications. She held this post until her retirement in 1951. Thereafter she worked in a temporary capacity until 1968 and as a private researcher until 1980.
Upon her return to the Division of Botany in 1927 Verdoorn continued her research and publication. One of her important early works was a revision of the genus Crotalaria in south and south-east tropical Africa (Bothalia, 1928). During her career from 1919 to 1984 she published some 300 papers and articles. Included were revisions of the genera Plinthus, Crinum, Waltheria, Cola, Melhania and sub-genus Hermannia as well as revisions of the families Oleaceae, Salvadoraceae, Loganiaceae, Gentianaceae, Zamiaceae and Welwitschiaceae for the Flora of southern Africa. She was in fact the major drive behind the latter project and also the major contributor of text in the Flowering Plants of Africa series. Many of her publications were aimed at developing an interest in botany in members of the public, for example, An introduction to botany and a few Transvaal flowers (1934), Edible wild fruits of Transvaal (1938) and articles in popular journals, in books for primary schools and in the Standard Encyclopeadia of Southern Africa (1970-1976). She also wrote one of the first Afrikaans textbooks on botany, Inleiding to plantkunde en tot enige Transvaalse veldblomme (1942).
During her many field trips she personally collected over 4000 plant specimens for the National Herbarium, plus many more jointly with other collectors. One of her most important collections was in the Salt Pan area north of the Soutpansberg. She also collected extensively near Fauresmith in the Free State and Middelburg in the Eastern Cape, and in various other places in southern Africa including Inhaca Island (Mozambique) in 1962 and annual collections during 1940-1949 in Zimbabwe. The genus Inezia was named in her honour by Dr E. P. Phillips*. Species named after her include Aloe verdoorniae, Senecio verdoorniae and Teclea verdoorniae.
In recognition of her botanical work the following publications were dedicated to her: Volume 28 of Flowering Plants of Africa, Volume 40 of the Journal of South African Botany, an edition of the journal Aloe (Vol. 2, No. 2, 1986), and A field guide to the trees of southern Africa by Eve Palmer (1977). The University of Natal awarded her an honorary PhD degree in 1967. She was a member of the South African Biological Society, received its Senior Captain Scott Memorial Medal in 1952, and served as its president in 1956/7. In 1964 she was president of Section B (which included botany) of the South African Association for the Advancement of Science. She was a founder member of the South African Association of Botanists and received their Senior Medal for Botany in 1980.
Verdoorn had a genuine love for and interest in people from all walks of life. She was a devout Christian and was characterized by a sense of humour and an enduring humility.
