Black and white photograph of borders, paths, and trees with spired tower in background

Celebrating 400 years of botany at Oxford University

By Danielle Czerkaszyn, Librarian and Archivist

John Phillips, Professor of Geology (1856-1874)

As a natural history museum, we are perhaps slightly unusual: aside from some fossilised plants, there are no botanic specimens in our collections. The reason for this is that when the Museum opened its doors in June 1860, Oxford Botanic Garden had already been around for a considerable 239 years, and it was considered unnecessary to move it.

Today, the Botanic Garden celebrates 400 years since its founding as the Oxford Physic Garden on 25 July 1621. To mark this anniversary we’ve explored our archive to highlight some connections between the Museum and Botanic Garden, in a relationship that continues to this day.

With its Pre-Raphaelite influence, the design of the Museum was conceived as an object lesson in art; both beautiful and instructive, it should teach students and visitors alike about the natural world. One of the most noticeable decorative teaching tools are the columns, capitals and corbels that surround the main court of the museum. Following Pre-Raphaelite principles, these were designed by Professor of Geology and the first Keeper of the Museum, John Phillips, who sketched most of the designs and outlined the order they would go in.

The plans called for 126 columns, 64 piers and 192 capitals and corbels. Each column was made from a different decorative stone from around Britain and Ireland, topped with a carved capital and flanked by a pair of corbels carved into plants representing the different botanical orders. As it was decided early in the design process for the Museum that the Oxford Botanic Garden would not move from the High Street, these carved plants were meant to ‘satisfy the botanist.’ Each column was supposed to be labelled with the name of the stone, its source, and the botanical name of the plant, but unfortunately only the geological inscriptions were completed.

James O’Shea carving the Cat window found on the front façade of the Museum, c. 1860

The carvings were created by ‘Nature’s own Pre-Raphaelites’ the O’Shea brothers, James and John, and their nephew, Edward Whelan. Working in collaboration with Charles Daubeny, Professor of Botany and head of the Oxford Botanic Garden, Phillips supplied the O’Sheas with specimens of the plants he had chosen, and so the carvings were made from life. Each capital is different and unique based on the plants they were representing. Some are simple and elegant while others are more intricate and hide small birds, animals and insects.

Phillips also worked with another curator at the Botanic Garden, William H. Baxter, who advised on suitable trees and shrubs to adorn the grounds surrounding the Museum. Over the years, as landscaping has changed and additional science buildings have been added around the Museum, only one of the trees chosen by Phillips and Baxter has survived. It is the imposing Giant Sequoia on the front lawn, which was planted in the early 1860s and is believed to be one of the oldest specimens in the United Kingdom.

Our connection to Oxford Botanic Garden continues to the present day. As the Museum embarks on the first major redisplay of its permanent exhibits in almost 20 years, staff are collaborating with the Garden to reference plants for displays showing the immense, interconnected variety of the natural world.

We are very pleased to be strengthening the Museum’s long relationship with the Botanic Garden, and would like to take this opportunity to wish everyone there a very happy 400th birthday!

Oxford Botanic Garden today
Top image: Oxford Botanic Garden in 1880

The Evolution of Plants

To mark Plant Appreciation Day today, Lauren Baker and Chris Thorogood of the University of Oxford Botanic Garden and Arboretum take us on a quick tour of the evolution of plants: from primitive water-dwelling algae to the colonisation of land, and the eventual success of angiosperms – the flowering plants.

The Earth formed around 4.6 billion years ago, and around 2.7 billion years ago the very first plants evolved. These were the algae, a diverse group that live mainly in water. The ancestor of all modern algae – and the first organisms to photosynthesise – were cyanobacteria. Green algae evolved from these cyanobacteria and are the ancestors to all modern plants.

We owe the air we breathe to plants. With the production of oxygen through photosynthesis came a drastic climatic shift around 2.4-2.0 billion years ago. Known as the Great Oxygenation Event, it dramatically increased oxygen and decreased carbon dioxide in the atmosphere.

Non-flowering plants

Jump ahead 1.5 billion years and the evolution of plants really takes off. To leave the water, plants needed to develop protection from drying out. The group that colonised the land is called the bryophytes, and includes the liverworts, hornworts and mosses.

Bryophytes are simple plants that lack true roots or ‘plumbing’ vascular tissue such as xylem or phloem. Bryophytes may have evolved from green algae in shallow, fresh water and developed the ability to survive on land when these pools dried out: 470 million years on, you can still see many bryophytes growing in damp habitats today.

A living bryophyte: Marchantia species growing in the Carnivorous House at Oxford Botanic Garden

The first vascular plants appear around 430 million years ago. One of the earliest examples was Cooksonia, consisting of a simple branching stalk without leaves.

Lycophytes, which evolved around 350 million years ago, also have vascular systems that enable water and nutrients to be moved around the plant. This drove the evolution of more complex, multicellular plants.

The ability to pump water allowed lycophytes to grow to heights of 45 m and they formed vast forests. Their remains also make up the coal, oil, and natural gas we use for energy today. More than 1,200 species of lycophytes exist now, grouped into three orders: the club mosses, quillworts and spike mosses.

A ‘living fossil’ that can be seen growing at the Botanic Garden is Equisetum, commonly called the horsetail. Horsetails evolved around 350 million and although the species alive today are herbaceous, extinct horsetails such as Calamites once formed large trees. The fossilised remains of Calamites in the collections of the Museum show the vascular tissues that would have carried water and nutrients up the vast trunk of the tree.

​Cycads also evolved around the same time as the lycophytes and horsetails. They could easily be confused with palms, but unlike palms they are not flowering plants. Cycads belong to a group of plants called the gymnosperms, a name that literally means ‘naked seed’, and refers to the plants’ reproduction with seeds that are not encased in an ovary. Cycads can survive for over 1,000 years and are very slow growing. Today, the majority of the 200 surviving species are threatened with extinction.

​Another ancient and unusual group of gymnosperms that evolved alongside cycads and lycophytes are Gnetophytes, which include plants such as Ephedra, Welwitschia, and Gnetum. There are about 40 living species of Gnetum, and they are tropical evergreen trees, shrubs and lianas. Before DNA sequencing technology, they were believed to be the closest living relatives of flowering plants due to the sugary sap they produce to attract pollinating insects, like the nectar produced by flowers.

Fossils of Ephedra date back as long as 120 million years ago. They are pollinated by both wind and insects, and are found across all continents except for Australia. With small, scale-like leaves they are highly adapted to arid environments, growing in sandy soils with direct sun exposure.

But perhaps the most familiar gymnosperms are the conifers. Conifers include the world’s oldest tree, the bristlecone pine, and the world’s largest tree, the giant Sequoia. There are over 615 species of conifers, most belonging to the pine family, Pinaceae.

Flowering plants​

The evolution of flowering plants – the angiosperms – 125 million years ago, was the start of a global botanical competition with gymnosperms, and it changed the appearance of our planet forever. The fossil record shows the earliest flowering plants bloomed alongside the dinosaurs, and probably looked something like a magnolia.

Magnolia stellata blooming at Oxford Botanic Garden

Unlike the gymnosperms, the angiosperms reproduce with flowers and their seeds are contained within protective ovaries. Despite their relatively late emergence, the diversity of flowering plant species was accelerated by their evolution alongside insect pollinators. Today, of the roughly 350,000 known plant species, 325,000 are flowering plants.

Bacteria that changed the world: Rhizobium leguminosarum

In our Bacterial World exhibition we offer a selection of ten bacteria that have changed the world, some in profound ways. In this series of short fact-file posts we present one of the ten each week. This week’s bacteria are…

Rhizobium leguminosarum
– the Crop-Boosters

Where they live
Rhizobia leguminosarum have a special relationship with plants, living inside little nodules on their roots and receiving shelter and food from them.

Why they are important
In return for its comfortable life, the bacteria bring about hugely increased crop yields. They enable the plant to use nitrogen from the air as a fertiliser, a process called nitrogen fixing.

How they are named
The family of bacteria called Rhizobia got its name in 1889 – it means ‘root living’. Leguminosarum indicates that the species lives in leguminous plants such as peas, beans and lentils.

How they work
The two-way relationship between plants and rhizobia is called mutual symbiosis. Scientists boost crop yields even further by selecting the best strains of bacteria to pair up with plants in specific environments.

Top image: Electron micrograph of root nodules with Rhizobium leguminosarum bacteria grown by The Rhizosphere Group (University of Oxford)
Copyright: Kim Findlay (John Innes Centre)