Inez Clare Verdoorn (15 June 1896 – 1989), was a South African botanist and taxonomist, noted for her major revisions of plant families and genera. She is also a niece of Eugene Nielen Marais, lawyer, naturalist, poet and writer. She has more than 200 botanical publications to her credit, including major revisions, appearing mainly in Bothalia, Flowering Plants of Africa, Flora of Southern Africa, Kew Bulletin, and the Journal of South African Botany. This botanist is denoted by the author abbreviation I.Verd. when citing a botanical name.