Bob Cleland

Dr. Robert Erskine (Bob) Cleland passed away peacefully in the evening of May 22, 2026 at the age of 94.

Bob was born in Baltimore, Maryland in 1932 to Elizabeth Prentice (Shoyer) Cleland and Ralph Erskine Cleland, both science faculty at Goucher College. The family moved to Bloomington, Indiana in 1938 when Ralph Cleland was hired to chair the Botany department at Indiana University. Bob grew up in Bloomington as the middle of three brothers, and then studied chemistry at Oberlin College. While at Oberlin, he traveled with his father to a professional meeting and developed a fondness for the field of plant physiology, specifically including the collegial atmosphere that he encountered. Bob then went to earn his Ph.D. at Caltech in 1957 with James Bonner, studying how plants regulate their rate and manner of growth. It was in Pasadena that he met Molly, who had recently moved there from Victoria B.C. to work as an X-ray technician. A shared love of adventure led ultimately to their wedding in 1957.

Following two post-doctoral appointments in Lund, Sweden and London, UK, Bob held a faculty position at UC Berkeley before joining the Botany department at the University of Washington in Seattle, where he remained for the rest of his career. This also brought the couple back nearer to Molly’s extended family in British Columbia, and many summer vacation days were spent on Vancouver Island, especially near Parksville. Bob just lit up around children, and led many exploratory missions to tide pools and across the enormous tide flats of Craig Bay. He was a particular fan of poking Pacific geoduck siphons with his toe to elicit “tide flat geysers”, and occasionally dug them out to show to the horde.

Bob’s academic story included a stint as president of the American Society of Plant Physiologists (now ASPB, where he became a Pioneer Member), membership on the governing board of the American Society of Gravitational and Space Biology, membership on multiple National Academy of Sciences committees and boards, and election as a Fellow of the AAAS. Bob also was a favorite, and award-winning, teacher, and a committed mentor with a wide open door. He built the first majors-level introductory biology course at the University of Washington; this led to the establishment in 1987 of the interdepartmental Biology Program, which Bob directed for several years. The Program was a major step in Bob’s dream of uniting the separate departments of Botany and Zoology, which ultimately did merge in 2003, shortly after Bob’s retirement (“retirement”).

Scientifically, Bob was one of the principal architects of the modern understanding of plant cell growth, in particular the mechanisms by which plant cells regulate the extensibility of the nonliving cell walls within which they are contained. Key players in this drama include the hormone auxin, which Bob and his Ph.D. advisor showed in 1956 causes a loosening of cell wall structure, and the acid growth theory, which Bob developed with his collaborator Dave Rayle starting in 1970, demonstrating and detailing the mechanisms of auxin-induced cell enlargement. Bob’s lab over the years was an exciting and collaborative environment, with students and postdocs descending often upon Bob and Molly’s house for dinner parties or other events.

Aside from science and family, Bob loved trains and rail history, sailing, and Northwest Indigenous art, and was a serious birder with a long life list. His extensive collection of railroad books and magazines endures at the Pacific Northwest Railroad Archive.

Bob and Molly traveled widely together across the world, continuing their tradition of shared adventure throughout their lives. They finally moved together to Bridges Cornell Heights in Ithaca, NY in December 2022 to be closer to their children. Bob is predeceased by his elder brother William Wallace (Mo) Cleland, sisters-in-law Catherine (Tina) Forrester Cleland and Marguerite Raine, and brother-in-law Robert (Roby) Love, and survived by his wife of 68 years Mary Love (Molly) Cleland, children Thomas and Alison, grandchildren Alec, Linsey, Haley, Jasmine, Anna, and Delma, younger brother Charles Frederick (Rusty) Cleland, sister-in-law Joan Cleland, and nieces and nephews Sean, Maureen, Elsa, Erica, and David and their families.

Bob is deeply missed. In his memory, in lieu of flowers, the family requests that you do something kind for other people.