Anne Ophelia Todd Dowden was born in Denver, Colorado, and grew up in Boulder. She spent her childhood collecting and drawing living things she found in the foothills of the Rocky Mountains. As a teenager, she made medical drawings for her father, who was the head of pathology at the University of Colorado Medical School. In 1930, she earned a degree in art from Carnegie Institute of Technology in Pittsburgh (now Carnegie-Mellon University), and shortly afterwards moved to New York City. In 1934, she married Raymond Baxter Dowden, also an artist. Ms. Dowden originally hoped to become a book illustrator, but after meeting with little success in this field, she taught drawing for 15 years at the Pratt Institute and then at Manhattanville College. She also designed floral printed wallpaper and drapery. When she was in her late 40s, she began to get regular freelance commissions from magazines such as Life, House Beautiful, Natural History, which enabled her to become a full-time botanical illustrator. She was in her 50s when she wrote, designed and illustrated the first of her 20 books, Look at a Flower (1963). She worked mainly in watercolor, producing elegantly detailed images of flowers, insects, herbs and birds. She is considered one of America’s leading botanical artists of the 20th century, and probably the most popular. Two of her books won awards from the American Library Association. Wild Green Things in the City: A Book of Weeds (1972) was the result of three years of research scouring New York City in search of specimens from warehouse and railway yards, parking lots, docks, and torn-down building sites.
Her work was also shown in museums and at botanical gardens, including the Smithsonian, the New York Public Library and the Denver Art Museum.