Cynthia Lindenberg Letty was born in Standerton, in the old Transvaal Province in 1895. She was the eldest of five children. At the outbreak of the South African War in 1899, the family moved to Estcourt in Natal. It is here that she attended the first of thirteen schools. Two years after the end of the war the family moved back to Standerton.
It was after their return to Standerton that Josina, an able and talented woman herself, gave her daughter her first lessons in painting veld flowers in watercolour. That would turn out to be the only guidance she would ever have, having had no formal training.
At the outbreak of World War I Letty enlisted and was posted to Europe. At the end of the war he never returned to South Africa. He died in France. Her mother had moved to Pretoria during the war, taking all the children with her.
She began painting in 1925, aged 30. Working at the Onderstepoort Veterinary laboratory, she had to record in detail the post mortem appearance of various animal diseases and abnormalities. This was before the time of colour photographs. She produced splendid work that propelled her to greater things.
In 1927 she was moved to the Division of Plant Industry in the Department of Agriculture where she painted flowers. She completed over 740 plates for Flowering plants of Africa, earning the distinction of being a leading botanical artist. Three of her publications featured in the new national monetary coin series in 1961.
In 1973 Letty illustrated and published Bothalia. She also published various other smaller works. Her contribution is remembered in the names Aloe lettyae Reynolds and Crassla lettyae Philips. She died on 3 May 1986, aged 90.