When botanist Katherine Esau died June 4, 1997 at age 99, Peter Raven, director of the Missouri Botanical Garden, remembered that she "absolutely dominated the field of plant anatomy and morphology for several decades. She set the stage for all kinds of modern advances in plant physiology and molecular biology."

Raven's comment reflects Esau's significant scientific contributions, but what is perhaps as impressive is the story of her remarkable and improbable journey from a childhood in Russia to a distinguished research career, which included 35 years at UC Davis as a student and faculty member.

Katherine Esau was born in the Ukraine in 1898. Her family fled to Berlin after World War I because Katherine's father, who was loyal to the Czar, feared Bolshevik persecution. So it was from Germany that Esau emigrated to the United States. The family entered the country at Ellis Island, but left New York to settle in the Mennonite community of Reedley, CA.

In 1924, Esau, who had studied agriculture in Russia and Germany, accepted a position working for the Spreckels Sugar Co. in Monterey, Calif. She was to develop a sugarbeet resistant to curly top-an economically ruinous viral disease spread by an insect called a leaf hopper. No one else at Spreckels was working on the project and Esau instituted a successful hybridization program.

When W.W. Robbins, then chair of UC Davis' botany division and the namesake of Robbins Hall, paid a serendipitous visit to Spreckels, Esau asked him about graduate studies at UC Davis. He responded by offering her a graduate assistantship.

Esau hoped to continue her research on developing the curly top-resistant sugarbeet at UC Davis, but after her initial year of graduate studies, she arrived at an impasse. Other UC Davis researchers had sugar beet fields they did not want infected with the curly top virus, which meant Esau could not release virus-laden leafhoppers in the open. Undaunted, she decided to focus her research on the effect of the curly top virus on sugarbeets, a decision that changed her field to pathological plant anatomy and led to the lifelong career Peter Raven praised so highly.

Once Esau received her doctorate in 1931, Robbins asked her to join the UC Davis faculty. One of her early publications as a faculty member reported her discovery that the curly top virus spreads through a plant via the food-conducting or phloem tissue. Esau's research on another host of the curly top virus, the tobacco plant, strengthened this concept.

The John Simon Guggenheim Foundation recognized in 1940 Esau's developmental studies and work on diseased plants by granting her a one-year fellowship. Six years later, Esau presented a review of the work she had done during her first 15 years at UC Davis when she was selected to give the Faculty Research Lecture, the highest honor the campus bestows for research.

In the late 1940s, in a house that still stands at 237 First Street, Esau began to write a manuscript that became the 735-page, classic textbook Plant Anatomy. Ray Evert, a former graduate student of Esau's and now chair of the botany department at the University of Wisconsin, Madison, recalls the book's influence on him when it was first published in 1954: "Dr. Esau's Plant Anatomy took a dynamic, developmental approach designed to enhance one's understanding of plant structure. The book Plant Anatomy brought to life what previously had seemed to me to be a rather dull subject. I was not the only one so affected. Plant Anatomy had an enormous impact worldwide, literally bringing about a revivification of the discipline."

Tom Rost, professor of plant biology, had a similar reaction. "I took my first plant anatomy course as a graduate student in 1963, and Esau's Plant Anatomy and the lab manual that went with it were the textbooks used. They hooked me on plant anatomy." Until it became unavailable in 1996, Rost continued to use an updated version of Esau's book for the plant anatomy course he teaches. However, he still uses photomicrographs prepared by Esau.

A shorter textbook by Esau, The Anatomy of Seed Plants, was published in 1960 and Professor Bill Lucas, also a plant biologist, still refers his students to it. "Katherine Esau's work is the Webster's of plant biology-it's encyclopedic," says Lucas. "Her prose is elegant and precise; each word is carefully chosen. When you read her publications, you're at the microscope with her-you see what she's seeing. If my students and I have a disagreement about cell definition, I turn to Esau's work to settle it." Lucas adds that Esau's book The Phloem is still the bible on that tissue.

During most of her tenure at UC Davis, Esau was housed in a building with no air conditioning that was supposed to have been used as a garage. She was still working in that building when in 1957 she was elected to the National Academy of Sciences, becoming the sixth woman to receive that honor. In addition to this prestigious award, she received the National Medal of Science from President George Bush in 1989. Rost underscores the distinction Esau brought to UC Davis when he comments, "As this campus's only National Medal of Science recipient, she is without a doubt our most prominent biologist." However, Esau was unaffected by the recognition accorded her, and she told David Russell, who compiled her oral history, "I don't know how I happened to be elected [for the National Medal of Science]. I have no idea what impressed them about me."

Esau began using the electron microscope for her research in 1960, two years before she left UC Davis for UC Santa Barbara. In 1969, she received a grant from the National Science Foundation for an electron microscope solely for her use. Yet she was as unimpressed by technological innovation as she was by the honors accorded her. When Russell asked what it was like to use an electron microscope for the first time, Esau replied, "Well, you know, I'm not such an impressionable person. I take my matters step-by-step as they go. You expect me to be 'Ahhh, Ooohhh.' I'm not like that at all. I'm a very mundane person."

Evert contradicts Esau's self-perception by describing her as having a stately, elegant demeanor reminiscent of Ingrid Bergman's in the film Anastasia. But this dignified aura belied a sense of humor manifested in a lecture titled "The Saga of Vladimir-the-Virus and the Sad Fate of Norman-the-Nucleus" in which Esau personified the cellular components involved in viral infection. Many of her lectures began with "Once upon a time..." and came to be known as "Esau's fables."

Esau gave the final lecture of her career at UC Davis in 1982 on plasmodesmata. She was 84 years old. Bill Lucas was present at the lecture and his reaction to it fittingly summarizes Esau's career: "It was brilliant."