Stuart Max Walters, botanist: born Outibridge, Yorkshire 23 May 1920. Research Fellow, St John's College, Cambridge 1948-51; Curator of the Herbarium, Botany School, Cambridge University 1949-73, Lecturer in Botany 1962-73, Director, University Botanic Garden 1973-83; Fellow, King's College, Cambridge 1964-84; married 1948 Lorna Strutt (two sons, one daughter); died Grantchester, Cambridgeshire 11 December 2005.
Max Walters was an authority on British and European plants and a key figure in the development of field botany in the second half of the 20th century.
At Cambridge, where he spent the whole of his professional life, he forged a late flowering of university botany. He organised the first mapping of British plants and the forging of the first European Flora as well as acting as host to a series of international conferences. He was also, in the earlier part of his career, a leading experimental taxonomist. Combining scholarship with natural teaching ability he wrote a series of semi-popular books on British and European plants, most of them jointly with other Cambridge colleagues.
With Franklyn Perring, Walters masterminded the BSBI (Botanical Society of the British Isles) Distribution Maps Scheme. This resulted in the publication of the Atlas of the British Flora in 1962, the first time the distribution of wild flowers, trees and ferns were mapped in detail. Walters was also a member of the distinguished team that, over three decades, compiled the Flora Europaea, the definitive five-volume account of all wild vascular plants found in Europe. He was joint editor of The European Garden Flora, a similar multi-volume work for plants cultivated in gardens. Perhaps his magnum opus was Plant Variation and Evolution (1969), co-written with David Briggs, a standard text which has held its own at universities and institutes for 30 years.
As Curator of the University Herbarium and later Director of the famous University Botanic Garden, Walters forged close links with European botanists, especially those isolated by political division behind the Iron Curtain. With his charm and a fund of good stories about people, places and events in the botanical world, Walters made Cambridge a congenial and welcoming place. While he was Director, his official residence in the Botanic Garden saw a seemingly endless procession of visitors from home and abroad. He and his wife, Lorna, made their home a relaxing and hospitable place for botanical discussions amid a pleasant atmosphere of cats, good food, tea and wine, and stimulating conversation.
Max Walters grew up in Stocksbridge, near Sheffield, where he absorbed the non-conformist Christian ideals of peaceful progress and hard work that sustained him throughout life. Encouraged by his parents to go on to higher education, he won a scholarship to Cambridge at Penistone Grammar School. He entered St John's College in 1938 where he read the Natural Sciences tripos, specialising in botany.
His studies were interrupted by war service. As a pacifist, on the outbreak of war Walters took up hospital work in Sheffield where he witnessed the savage German air-raids on the city in 1940-41. He later moved to a hospital in Bristol. After the Second World War he returned to Cambridge, graduating with a First in 1946, and subsequently became a research fellow. His PhD, which he obtained in 1949, was on the taxonomy of a small and difficult group of plants called spike-rushes (Eleocharis). He was also awarded a DSc in 1975. He married his childhood sweetheart, Lorna Strutt, in 1948.
Since childhood Walters had been fascinated by plants in the field, especially their natural variation and their relationship to their habitat. His first love was for mountain plants, and in 1938 a travelling scholarship enabled him to spend the summer at a Swiss botanical institute, where he studied alpine plants. After the war he also spent a summer at Uppsala, the birthplace of Linnaeus, where he learned Swedish from a granddaughter of Strindberg.
A Botany School trip to the Cairngorms gave him a lifelong interest in another group of closely related species, the lady's-mantles or Alchemillas. Other plants on which he became an acknowledged expert included violets, parsley pierts and Montia. He discovered several new British plants, including Aphanes microcarpa in 1949, Alchemilla subcrenata in 1952 and Eleocharis austriaca in 1963.
His knowledge of the minute particulars of plants made Walters a natural choice for Curator of the University Herbarium, one of the oldest and most important in the UK. He became a lecturer in botany in 1962, and was made a Fellow of King's College two years later. He wrote two well-known books for the New Naturalist library, Wild Flowers (1954, co-written with John Gilmour) and Mountain Flowers (1956, with John Raven). Both embodied the spirit of what Walters called "herborising": "a carefree shared experience in the field". One of his happiest memories was the tour of the Scottish Highlands he made with Raven in the late summer of 1953 in preparation for writing Mountain Flowers.
While forging productive links with European botanists and botanical institutions, Walters was also deeply interested in plant life at home. A regular contributor to the journal Nature in Cambridgeshire, he also helped to set up the Cambridgeshire Naturalists' Trust in 1956. He served the trust twice as Secretary and also as its chairman. He was much involved in the research and management of Wicken Fen, England's oldest nature reserve.
With Franklyn Perring and Peter Sell, he compiled the Flora of Cambridgeshire (1964), the first comprehensive account of the county's wild plants for over a century. His The Shaping of Cambridge Botany (1981) was a historical account of the county's long line of distinguished botanists, beginning with John Ray in the 17th century. With Anne Stow, he also wrote, in 2001, Darwin's Mentor, a biography of the neglected Cambridge botanist John Stevens Henslow, best remembered as the teacher, mentor and lifelong friend of Charles Darwin.
Walters took the University Botanic Garden into the forefront of plant conservation. One of his innovations was the much-visited garden of rare wild flowers from the Breckland district of East Anglia. Another was educational projects involving local teachers and schools. In retirement he drew on his unrivalled experience of horticulture and the natural environment to write Wild and Garden Plants, which linked garden varieties with their wild ancestors.
In 1984, Walters received the Victoria Medal of the Royal Horticultural Society in recognition of his contributions to botany and botanic gardens. Eleven years later he was awarded the Linnaean Medal for Botany for his work on British plants. Since his retirement, Walters lived in Grantchester where he cultivated his private botanic garden, full of wild British and European plants. He was also much involved in church activities and served as churchwarden of Grantchester for many years.