Randolph began working as a teaching assistant under Sharp in the winter term of 1922. They then started to apply the smear technique to pollen cells of corn and hypothesized the origin of
polyploidy in Maize. Randolph and McClintock's study techniques were very different. Randolph was very careful, cautious and meticulous, where as McClintock liked to try out and modify new techniques. Randolph ended their collaboration and McClintock began to work under Sharp, who gave her more freedom. But he stilled carried on his maize research, and in 1932, he published 'Some effects of high temperature on polyploidy and other variations in Maize', in
Genetics Vol.18 on page 222–229. Randolph and his wife Fannie made several trips to Europe collecting irises. They travelled to England (between 1936 and 1939, also in 1950 and 1959),
France (in 1950 and 1954),
Denmark (in 1950), and
Sweden (in 1950). He also led expeditions in search of new forms of iris, including
Iris pumila. In a complaint letter to
Marcus Morton Rhoades (Editor of Genetics journal) in 1942, he criticised Barbara McClintock's editing the work of a pupil of Randolph's. Calling her a
prima donna, who wants to be the
goddess of science and
godmother to aspiring young scientists everywhere. He was appointed chairman of the Scientific Committee of the American Iris Society, between 1945, and 1946. He started the counting of chromosomes of iris, growing seeds
in vitro and classification of the genus. Finding and publishing
Tripsacum zopilotense Hernandez-Xolocotzi, E. & Randolph, L.F. in 1950, in
Guerrero, Mexico. In 1954, he went to Europe and the Middle East on an iris hunting field trip, which included
Switzerland, France,
Italy,
Yugoslavia, Germany,
Austria,
Cypress,
Turkey,
Lebanon, and
Egypt. He then spent six months in 1957–58 at
Aligarh Muslim University in
India with a
Fulbright Award, In 1959, he wrote and had published
Garden Irises, which has 575 pages. Within the book, the chapter, 'Chromosomes of Garden varieties of Bearded Iris',(pages315-324) showed his academic interest. He also re-organised the William Dykes classification of irises, by moving certain irises into different sections and subgenra. This classification is still used by the American Iris Society. He served as the vice president and then became the 9th, Randolph and his wife, kept an extensive collection of iris in his garden at their home in Ithaca, which attracted many visitors. After nearly 40 years at Cornell, he retired in 1961, but started working part-time during the winters, at the
Fairchild Tropical Garden, in
Miami,
Florida as a research collaborator. Including work on
Tripsacum grasses, He then spent his summers back home at Ithaca. The species was named after Ira S. "Ike" Nelson, professor of horticulture at the
University of Louisiana,
Lafayette, and one of the founders, and early show managers, of the Society for Louisiana Irises. Nelson collaborated with Randolph, and together they identified
Iris nelsonii, and Randolph named it after Nelson. In 1967, Randolph, I.S. Nelson and R.L. Plaisted published 'Negative evidence of introgression affecting the stability of Louisiana Iris species' Cornell Univ Ag. Exp. Station Mem. Vol.398 (pages 1–56). This paper reviewed the morphological and pollen fertility data collected for
Iris fulva,
Iris brevicaulis and
Iris hexagona and other hybrid iris populations. He concluded that between the Louisiana iris species was localized hybridization. In 1976, he published 'Contributions of wild relatives of maize to the evolutionary history of domesticated maize: a synthesis of divergent hypotheses in Economic Botany, Vol.30 (pages321-345), which discounted the role of
teosinte as an ancestor of maize. Lowell died in Ithaca in 1980. ==Awards and honours==