Farr sitting in lab with microscope. Wanda Margarite Kirkbride Farr (January 9, 1895 - 1983) was an American botanist known for her discovery of the mechanism by which cellulose is formed in the walls of plant cells. She worked as a researcher at the Barnard Skin and Cancer Clinic where she performed microscopy on live animal and plant cell cultures. When her husband died in 1928 she began research related to her late husband's work studying the growth of root hairs in plants. She became Director of the Cellulose Laboratories at the Boyce Thompson Institute for Plant Research, doing pioneering work on cellulose synthesis and plastids. She discovered that cellulose-manufacturing plastids do exist in the protoplasm of the cell, but that such plastids had been invisible because they have a light refractive index similar to that of the protoplasm in which they are located. She made the plastids visible in cotton cells by mounting the cells in a new bath derived from the juices of the cotton plant rather than in water, which had been used previously. In 1956, she established her own laboratory, Farr Cytochemistry Lab, in Nyack, New York. She died in 1983 at the age of 88.