Agnes Arber

Agnes Arber FRS ( Robertson; 23 February 1879 – 22 March 1960) was a British plant morphologist and anatomist, historian of botany and philosopher of biology. She was born in London but lived most of her life in Cambridge, including the last 51 years of her life. She was the first woman botanist to be elected as a Fellow of the Royal Society (21 March 1946, at the age of 67) and the third woman overall. She was the first woman to receive the Gold Medal of the Linnean Society of London.

Her scientific research focused on the monocotyledon group of flowering plants. She also contributed to development of morphological studies in botany during the early part of the 20th century. Her later work concentrated on the topic of philosophy in botany, particularly on the nature of biological research.

Personal life and education Agnes Robertson was born on 23 February 1879 in Primrose Hill, London. She was the first child of Henry Robert Robertson, an artist, and Agnes Lucy Turner, and had three younger siblings, Donald Struan Robertson (who later became Regius Professor of Greek in the University of Cambridge), Janet Robertson, who later became a portrait painter, and Margaret Robertson (married name Hills), who was a notable suffragist and local politician. Her father gave her regular drawing lessons during her early childhood, which later provided her with the necessary skills to illustrate her scientific publications herself.

At the age of eight Robertson began attending the North London Collegiate School founded and run by Frances Buss, one of the leading proponents for girls' education. Under the direction of the school's science teacher Edith Aitken, Robertson discovered a fascination with botany, publishing her first piece of research in 1894 in the school's magazine and later coming first in the school's botany examinations, winning a scholarship.

It was here that Robertson first met Ethel Sargant, a plant morphologist who gave regular presentations to the school science club. Sargant would later become her mentor and colleague, having a profound influence on Arber's research interests and methods. She was an excellent draughtsperson and often illustrated her books herself; she drew about a third of the illustrations in Water Plants.

In 1921, the "botanical establishment" denied Arber the 1921 presidency of British association for the advancement of science (BAAS)'s Botany section (Section K). This process was initiated by Frederick Orpen Bower, based on the premise that Arber should not follow Saunders immediately as president as both were women from Cambridge and that there were more senior male botanists up for the presidency. This reflected an antipathy against Arber not only as a female botanist but also as a Cambridge botanist. He claimed that Edinburgh (where the meeting was held) "has the right to expect better than this... To ask Balfour [of Edinburgh] to sit under the Presidency of Mrs. Arber is ridiculous!" Albert Seward met with Arber, who withdrew her candidacy and resigned as the secretary of the BAAS.

In 1925 Arber published her third book The Monocotyledons. The Editors of the Cambridge Botanical Handbooks series had asked Ethel Sargant in 1910 to prepare a volume on the monocots for this series. However ill-health and advancing years made it almost impossible for Sargant to complete the book, and in 1918 she suggested Arber to complete the work. The book was preceded by 10 papers in The Annals of Botany detailing the results of her research.

Arber had been introduced to the work of Goethe while at school and remained fascinated by his ideas about botany. Arber discusses the processes behind forming a concept from research and examines the philosophy of plant morphology. Arber uses this to examine the structure of flowering plants, and proposes the partial-shoot theory of the leaf. According to this theory, each element of the plant is a shoot or a partial shoot. Leaves are partial shoots that show reduced growth capacity. She mentions: "the leaf is a partial-shoot, revealing an inherent urge towards becoming a whole shoot, but never actually attaining this goal, since radial symmetry and the capacity for apical growth suffer inhibition". The parallelism of leaf and shoot dates back to Goethe, who first described compound leaves as in "reality branches, the buds of which cannot develop, since the common stalk is too frail". For Arber, compound leaves are clusters of united partial-shoots. Recent developmental genetic evidence has supported aspects of the partial shoot-theory of the leaf, especially in the case of compound leaves.

Her studies on the philosophy of plant morphology led her to take a broader view of the links between science and philosophy.

Recognition and awards In 1921 she accepted the annual position as president of the botany section of the British Association for the Advancement of Science, following Edith Saunders the previous year, but soon resigned after some members indicated that they did not want two successive women presidents. When she was offered the presidency again in 1926, she did not accept. In 2024 one was attached to her Cambridge home where she also carried out much of her research.

In May 2024, a new sponsored Agnes Arber PhD thesis prize in comparative biology at the University of Cambridge was created. Professor Sam Brockington, of Cambridge University Botanic Gardens, said that he hoped the prize "will support the next generation of pioneering botanists, following in the footsteps of Agnes".

Selected publications