Sunday 9 September 2018

Meeting Kew’s Daisy Experts


Close-up of bee on brightly-coloured daisy family flower


Insects love the Daisy family. Daisies were my first botanical love as I sat on my grandparents’ front lawn. Their showy flowers cheer us with a profusion of colour and the happy sound of buzzing bees.

It was with great relish that I visited Kew Gardens for the latest in the popular series of Meet the Expert tours. September’s focus is on Compositae (Asteraceae), more generally known as the Daisy or Sunflower plant family. In the first tour of the month, Dr Nick Hind, Kew’s Compositae expert and Lucy Bell, horticulturalist on the Great Broad Walk Borders shared their knowledge and enthusiasm with our lucky group of multinational visitors.


Compositae or Asteraceae are the world’s largest family of flowering plants. They grow on every continent except Antarctica. Kew’s State of the World’s Plants 2017 estimated the family’s size at 1,600 genera with 32,581 species. September is a particularly good time to admire their late summer colour.

Echinacea, Cone Flower

History
The tour began at the edge of Kew’s Great Broad Walk Borders. Kew has relatively few herbaceous borders, as its main focus is on plant science, conservation and research. Lucy Bell explained the history of the Great Broad Walk Borders. The Broad Walk is a wide path that runs from the Palm House to the Orangery. Kew’s first official director, William Hooker, appointed Decimus Burton as its architect and William Nesfield as landscape architect.

What’s in the name?
The existing borders maintained by Lucy and her assistant Maya are 3 years old and were created as part of a colourful redesign. Lucy drew our attention to the radiate heads of the family with its ray and disk florets. What most of us assume is a single flower is in fact a series of compact inflorescences. These composite flowers are the origin of the daisy family’s oldest Latin name of Compositae. Asteraceae is accepted as an equally valid family name. It is named after the star-like inflorescence of the Aster, the first-named or type genus in the family.

Aster, daisy family flower
Star-shaped flower


Pollination
A wide range of pollinators visit the Daisy family. As if on cue, the pollinators arrived on Helenium. The flowers open systematically The red and yellow ray florets attract pollinators to the discoid florets. The changing shape of the flowers help ensure that bees do not waste time with already pollinated flowers.

Other Compositae on view in the Great Broad Walk Borders were: Achillea, Aster, Centaurea, Cichorium, Cynara, Echinacea, Echinops, Heliopsis, Inula, Ostospermum, Rudbeckia and Symphyotrichum.

Achillea

Gardening Advice
For the gardeners in our group, our expert horticulturalist extolled the virtues of the Chelsea Chop. This term refers to the practice of reducing plants by a third in May around the time of the RHS Chelsea Flower Show. It seems brutal at the time. The rewards are reduced staking and more compact growth.

Rudbeckia
In the Kew Herbarium
For the second part of the tour, our group were lucky to go behind the scenes on an exclusive visit Kew’s Herbarium. Our expert, Dr Nick Hind, met us there. He is Kew’s expert in the scientific research and conservation of Compositae. He proudly advised that he is Kew’s oldest member of staff, but his enthusiasm for Kew, the Herbarium and his research subject are self-evidently undimmed. In fact, not only did we learn about the purpose and functioning of the Herbarium, we also heard more about the building’s architecture than I heard during my 2017 Open House London tour.

Dr Nick Hind in Kew's Herbarium with open Rubiaceae cabinet behind

Dr Hind Explains Herbaria
Dr Hind explained that a herbarium is a store of pressed, dried plants. We heard about the process and labelling in detail. Kew’s Herbarium is one of the largest in the world. At the mention of fireproof cabinets, my blood ran cold thinking of the devastating fire at the Brazilian National Museum just the day before. The fire has underlined the importance of digitising Kew’s collections and those of other precious collections worldwide. The original specimens remain irreplaceable.

In the Newer Vaults
Following a reorganisation, the two largest collections, Compositae (Asteraceae) and Leguminosae (Fabaceae) were rehoused. Dr Hind took us into the modern Compositae vault. Gone are the cupboards. Specimens are stored in fireproof boxes in compactor shelving to optimise space. The vault is air-conditioned and temperature-controlled between 14 and 15°C. Beetles are the bane of every herbarium curator. The low temperature prevents them from breeding. If two spells of freezing aren’t enough before the specimens arrive in the vault, any recalcitrant beetle will soon find itself headed for the freezers again just two floors away.

Dr Hind claimed or admitted that he is the person responsible for the reclassification of the Michaelmas Daisy within the family. Gardeners may find this confusing, however the name changes reflect advances in DNA research and increased botanical understanding.

As well as showing us specimens collected by Charles Darwin, Dr Hind shared his latest work with us. He is currently working on an article for Curtis’s Botanical magazine on Echinacea tennesseensis. This is a long-flowering plant with beautiful pink ray florets and erect stem. Inevitably, herbarium specimens lose colour in the drying process. By placing a botanical drawing alongside, Dr Hind brought the specimen’s full glory to life.

As we left the building, we were lucky to meet the talented Japanese botanical artist, Masumi Yamanaka, with her flower specimen in hand. As much we value digitisation to preserve the past, we must surely retain the breathtaking skills of botanical artists too. Digital copies can have the unfortunate habit of becoming inaccessible due to software updates. Original artworks continue to enthrall and inspire across the ages.

The tour overran, such was the enthusiasm of our expert guides. I’m looking forward to my next tour.

The Compositae tour will be repeated at 11.30am on Tuesdays in September 2018. I noted that due to popularity, the booking system for Kew’s Meet the Expert tours has changed. You now need to book a free ticket on entry via the kiosks at Victoria Gate. You can book from 10am. There are only 15 places each Tuesday so it is best to book as early as possible to avoid disappointment. You will be collected from Victoria Plaza/the information desk just before or at 11.30am. Enjoy!


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