Mary Grierson was born in Wales in 1912. From an early age, she showed a talent for drawing and painting. She graduated from the Royal Drawing Society in London in 1930. She had a predilection for botanical illustration and preferred watercolor to oil paint. From 1960 to 1972, she was the botanical illustrator & artist at the Royal Botanic Gardens, Kew. Grierson had a special talent for detailed drawing. At the invitation of M.H. Hoog, director of Van Tubergen in Haarlem, she drew at the Van Tubergen nursery every spring from 1973 to 1978. There, she created approximately 50 watercolors of bulbous plants, including these two in the De Witte Zwaan collection. The drawing of the Allium flavum is reproduced in the Van Tubergen autumn catalog for France from 1975. The Allium is listed there as no. 1306 with the addition "nouveauté."