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In Memoriam: Mary Leolin Bowerman 1908–2005

Barbara Ertter

Mary Leolin Bowerman
Mary on top of Mt. Pinos
Inspired by their botany teacher at Pasadena Junior College, two young friends entered the University of California at Berkeley in 1928. Here they would both find their respective life-time passions and arenas for accomplishment, involving geographic areas with which their names would become irrevocably linked. For Annetta Carter, this proved to be Baja California, thanks to the generous patronage of Annie Alexander and Louise Kellogg. For Mary Leolin Bowerman, the flora, ecology, and conservation of Mount Diablo became an all-consuming focus, with a digression into British Columbia along the way.

Mary, known to her friends at the time as Leo, was strong-willed and a bit of a rebel, making choices and decisions as she saw fit (e.g., favoring boys' haircuts and clothing). The only child of relatively well-to-do parents, she was born in 1908 in Toronto, Canada, and spent some years in England before ending up in southern California as a teenager. Her parents, who had hoped to see her go to Stanford and become a physician, instead joined her in the East Bay.

Coinciding with the onset of the Great Depression, Mary and Annetta received their A.B.'s in botany with 5 other graduates, all women, in 1930. The two friends remained at UC to pursue master's projects, at one of those heady times when a cohort of exceptionally talented and inspired students overlapped and contributed to synergy of ideas from which all benefited. Notable among Mary's fellow students were David D. Keck (Ph.D., 1930), Katherine Esau (Ph.D., 1931), Herbert Mason (Ph.D., 1932), Lincoln Constance (Ph.D., 1934), and Daniel Axelrod (Ph.D., 1938), who were destined to make significant advances in fields as diverse as biosystematics, plant anatomy, and paleobotany.

When Mary started at UC, Willis Linn Jepson was the reigning professor of vascular plant systematics. When Mary began her graduate work in 1930, however, Jepson was on leave, visiting distant herbaria and participating in the International Botanical Congress in Cambridge, England. It was Herbert Mason, acting as Jepson's assistant, who first directed Mary toward Mount Diablo as a floristic project. At that time, it was common for botany majors at UC to be assigned the flora of a local peak. Constance, for example, was doing a floristic survey of Redwood Peak in the Oakland Hills, published in 1932. As one of the only botany students to own a car, Mary was granted Mount Diablo, surely a plum in its stately dominance of the East Bay landscape.

In later years, Mary delighted in relating how she had the effrontery to inform Jepson (her Major Professor) that the Mt. Diablo project was going to be her doctoral project, not just a master's thesis. Although taken aback by Mary's boldness, Jepson concurred, presumably influenced by the extent to which Mary was going well beyond a simple floristic checklist. The final product, published as a book in 1944, was in fact trend-setting in several respects, notably in the inclusion of ecological information when ecology was still a new, and somewhat suspect, addition to the family of biological sciences. As noted in the forward, "This is the first attempt in California to describe the habits of each species individually. The habitat, altitudinal range, abundance, period of blooming, associated species, and distribution upon the mountain have been independently determined for each species." Concurrent studies and revolutionary new ideas by Mary's fellow students were also incorporated; e.g., the Geoflora concept of Daniel Axelrod, and floristic assemblage comparisons with Mount Hamilton, then being studied by Helen Sharsmith. Overview discussions of climate, soils, geology, paleobotany, collecting history, and especially plant communities comprise the first third of The Flowering Plants and Ferns of Mount Diablo, California, with keys and synopses of each species occupying the remainder.

It took Mary six years to complete the requirements for her Ph.D. (1936), and another eight years for the resultant book to be published. Parental resources allowed Mary to remain financially independent, a particular boon during the war years when suitable jobs were few and far between. The apparent drawback, however, was that without the external pressure to produce, Mary's perfectionist streak was left unfettered. In a 1940 letter to one of his favorite former students, Jepson expressed his frustration with this aspect of Mary: "Poor girl! She is seeking the impossible for her thesis - now six years plus 4 years old. . . . She would like, however, to talk it all over from now until Doomsday. She cannot reach decisions!"

What kept Mary busy during the years following the publication of her grand opus in 1944 is a bit of a mystery. Evidently fieldwork on Mount Diablo continued, but the expectation of a new, updated edition somehow remained unmet even after the original book was long out of print. A primary competitor for Mary's attention during this period was the flora of British Columbia, triggered by the collections and influence of Thomas T. McCabe. McCabe, a research associate at the Museum of Vertebrate Zoology, had made extensive animal and plant collections in remote parts of British Columbia during the 1930's and 1940's. Perhaps influenced by her own Canadian roots, Mary began preparing a flora of British Columbia based on McCabe's extensive collections. This project suffered a serious setback when McCabe died of a heart attack in 1948. Mary's determination to finish the flora remained strong, but the manuscript was both incomplete and increasingly outdated as the years went by.

McCabe's was not the only death impacting Mary's life during this period. Jepson had died two years previous, leaving the endowment that subsequently established the Jepson Herbarium. Mary's father died several years later, in 1954, at which time Mary and her mother moved to the house in Lafayette that would be their home for the rest of their respective lives. Mary's mother lived to 1980, dying at the age of 108, and was a major presence in Mary's life throughout this time. As another setback, a developing space crunch at the University Herbarium resulted in the loss of work space for Bowerman at UC. The specimens she was working on were moved to her home in Lafayette, returning to the herbarium years later. Mary's scientific interest in Mount Diablo, while remaining strong, became increasingly eclipsed by the urgent need to ensure the preservation of the mountain's natural character in the face of galloping development pressures. Mary began her study shortly before a mere 1,463 acres at the top of the mountain were set aside as a state park in 1931; Mary's fieldwork largely took place on private lands. Public holdings had expanded to 6,788 acres by 1971, but most of Mary's favorite piece of earth was still in great danger of being carved up into view lots. In 1971, Mary and Art Bonwell, an electrical engineer at DuPont, organized a meeting that resulted in the establishment of Save Mount Diablo. Mary's commitment to this cause became her crowning accomplishment, for which she received multiple awards (as listed in biography at

Mary's connection with the University of California, and the Jepson Herbarium in particular, was reinitiated in the early 1980's, when she became a significant contributor for the first edition of The Jepson Manual. In 1994, Mary agreed to lead a field trip to Mount Diablo in conjunction with the first Jepson Herbarium Symposium. This in turn led to a collecting trip to the summit of Mount Diablo on June 19 with Barbara Ertter, who was unable to attend Mary's field trip because she had been responsible for one herself.

Mary Leolin Bowerman
Mary and Barbara hit it off well enough that arrangements were made in 1995 for the Jepson Herbarium to take on the challenge of updating The Flowering Plants and Ferns of Mount Diablo, by then an increasingly hard-to-obtain collector's item. Barbara tackled the taxonomic updating, various sections were "farmed out" to appropriate specialists, and Susan D'Alcamo served as project "midwife." Funds provided by Mary allowed graduate student Lisa Schultheis to serve as technical editor, beginning with the scanning of the original edition. What was initially intended as a straightforward 2-year update reached completion in 2002, with the publication of a second edition by the California Native Plant Society. Amazingly, the number of species known from Mount Diablo was increased by one-fourth, a combination of new weeds, taxonomic "splits", and outright new discoveries.

Blessed with good genes and a temperate life-style, Mary entered her 90's in excellent health and continued to enjoy walks on her beloved mountain whenever possible. Declining health was evident by age 95, and after several hospital stints she passed away on 21 August, 2005, at age 97. Fortunately, this was not before she was able to enjoy the celebrated rediscovery of the Mount Diablo Buckwheat (Eriogonum truncatum), which Mary had been the last person to see nearly 70 years previous. Mary was interred with her parents at Chapel of the Chimes in Oakland, and a memorial was held for her at Mitchell Canyon on 9 October.

Mary is remembered by those fortunate enough to know her as unfailingly courteous and cheerful, balanced against the dogged persistent streak that made her such a capable advocate for Mount Diablo. She retained her identity as a botanist first and foremost, such that her conservation battles were always based on solid science. Mary's careful management of financial resources allowed her to be generous with friends and causes that she supported. The Jepson Herbarium is honored to be a recipient of that largesse, which will ensure that her dedication to co-author Barbara can be fulfilled: "With appreciation for all that you have done to update our book, and with encouragement to accomplish your vision of yet another future edition. With affection, Mary B. December 6, 2002"

Ertter, Barbara. 2006. In Memoriam: Mary Leolin Bowerman 1908–2005. The Jepson Globe 16(3).