Today we have our ‘Board Member for a Cleaner, Greener Oxford’ but 400 years ago the city’s recycling efforts were all down to ‘ye Universitie Scavenger’. Between 1621-26 this hard-working person delivered ‘4,000 loads of mucke & dunge’ from kitchens and privies to improve the soil of the recently-established Oxford Botanic Garden, then called the Physick Garden because of its focus on medicinal plants.

This is one of several Oxford-related stories that Stephen Harris unearthed while writing Planting Paradise: Cultivating the Garden 1501-1900. The book provides a historical perspective on the development of botany until the emergence of modern genetics, and explores how humankind has sought to discover, understand and use our planet’s plants for subsistence, health, wealth, and pleasure.

Since 1995, Dr Harris has been Druce Curator of the Oxford University Herbaria, responsible for around one million dried and pressed plant specimens collected over the centuries by botanists and explorers both famous and forgotten — and even some obtained by a pirate, William Dampier, in Western Australia in 1699.

The oldest herbarium in Dr Harris’s care is a book of about 300 specimens gathered around Bologna in 1606 by the Capuchin monk Gregorio da Reggio and later given to the botanist and diplomat William Sherard (1659-1728). At some point it disappeared and was only rediscovered in the late 19th century in the coke-house of Oxford’s Botanic Garden, wrapped in sacking but in surprisingly good condition.

“The technology of plant pressing has become a bit more refined in terms of the structure of the press, etc,” explains Dr Harris, “but it hasn’t changed much in 500 years.” Today’s botanists still carry presses on their expeditions. When in the humid tropics they sometimes submerge the entire press in alcohol to prevent the plants rotting, or speed up drying with a paraffin heater or even an open fire.

Some species present special challenges, for example fragile algae and watery succulents. But properly pressed plants are durable, providing they are kept in a dry, fungi- and insect-free environment.

Dried plant collections are important because they provide scientists with concrete evidence that a particular species existed at a specific location at a certain point in time. But they need looking after “if they are to remain of scientific value rather than drift into mediocrity or become mere historical curiosities” writes Dr Harris. He must ensure that the university collection remains relevant to the scientists who come from all over the world to see the specimens, and must selectively add new material. At present there are about 500 acquisitions each year, including many tropical tree specimens from Sierra Leone and Liberia.

Complementing the dried plants is the university’s collection of botanical books, and Planting Paradise is generously illustrated with some of the most striking images from these, including several elaborately allegorical title pages.

“People often don’t look at title pages but during the 17th and 18th century they often said an awful lot about people’s views on where plants came from, and some of their misconceptions.” One of his favourites is the title page of John Parkinson’s Theatrum Botanicum (1640), crowded with drawings of familiar and exotic plants from Europe, Asia, Africa and the New World, overseen by Adam and Solomon and with a rhino, zebra and llama thrown in for good measure.

Dr Harris is also a university research lecturer with an interest in plant genetics. For his doctorate he investigated the progeny of Oxford ragwort, which spread throughout Britain in the 19th century, helped by ‘prelate dispersal’ by clergymen trained in Oxford taking a botanical souvenir of the city to their parishes.

He has previously written and contributed to several books, including The Magnificent Flora Graeca: How the Mediterranean came to the English Garden and the more academic Plants, Health and Healing: On the Interface of Ethnobotany and Medical Anthropology, co-edited with Elizabeth Hsu.

He was also the botanical advisor for artist Sarah Simblet’s recent Botany for the Artist: An Inspirational Guide to Drawing Plants, which is illustrated with many delicate and beautiful drawings she made of specimens in the Herbaria, twisted and taped exactly as she found them.

* Planting Paradise: Cultivating the Garden 1501-1900 by Stephen Harris, is published by the Bodleian Library at £29.99.