Category: flowering plants

Tea, thatch and early spring

Posted on by andy.winfield

Today as I write this the sun is shining, the birds are in full voice singing, cawing and screeching around the Garden. Bulbs are popping up, crocus are the first with daffodils a week away from carpeting the ground with yellow. Primroses are dotting grassy areas and bees are beginning to forage in the middle of the day; the minimum temperature that a bee can fly is said to be 13 degrees, so when you see one out and about you know the season is changing. In February in this part of the UK we get an extra two and a half minutes of light every day; after February and through March to June it is only two minutes. This is why a lot seems to change in February in the Garden, it is a conduit for spring; the end of January is incomparable to the beginning of March in terms of light, flower and the beginnings of warmth. We’ll still get ice, cold, wet and maybe even snow again between now and summer, but days like this make us feel that winter is nearly behind us.

Crocus appearing in the Garden.

In the Garden there are exciting changes happening. Our South African display has had the framework of a traditional African roundhouse present for much of last year; as I write this it is being thatched with a South African reed called Cape thatching reed; Thamnochortus insignis, the building will then be rendered in a red cob. These features are important for bringing context to the plants around it, being a talking point and attracting people to the Garden where they can leave with maybe a lot, maybe a little, but some new knowledge of the plant world that they didn’t have before.

Lu Yu.

Another development is our Chinese tea plantation. Yes, a tea plantation here in Bristol, just a small one but a tea plantation none the less. When landscaping the area where we’ll grow tea, visitors ask what I’m doing and seem intrigued and interested with the response. Tea is something that is in the heart of UK people, many conversations, moments of relaxation, tears and laughter have happened over a cup of tea and many millions of hands have been warmed on a mug during winter. In China tea drinking dates back 5000 years. Legend has it that Emporer Shen Nung was boiling water when leaves from a wild tree blew into his pot; he was so interested in the aroma that he drank some. He named the brew ch’a, meaning to check or investigate. Tea became integral to the culture of China when Lu Yu, a Chinese scholar, dedicated his life to the study of tea; he wrote a treatise called ‘ The Classic of Tea’ in 760CE, the earliest work dedicated to tea. Today every Chinese household will have tea brewing sets and use tea brewing as a form of welcome, celebration, in family gatherings or to apologise. We’re looking forward to planting our fifteen (so far) Camelia sinensis plants; they should be in the ground by March, which, coincidentally, is when our refreshments open again after the winter…

We look forward to seeing you in the Garden, keep your eyes on the ground and enjoy early spring!

The new Australian display

Posted on by andy.winfield

By Helen Roberts

The newly established Australian display is thriving at the University of Bristol Botanic Garden. This new area has been developed over the last year few years with the aim of introducing visitors to the captivating flora from the Mediterranean climatic region of Western and Southern Australia. The new display is part of the strategic plan for the Garden and follows on from the creation of the Mediterranean and southwest South Africa zones (N Wray 2017, personal communication, 27th July). 
The Australian display still under development
at the Botanic Garden.
This display aims to broadly showcase some of the hardier plants of Western and Southern Australia but also concentrates on the highly diverse flora of the “Kwongan“, one of a number of special habitats that make up the Southwest Australia ecoregion. This ecoregion is acknowledged worldwide as one of the world’s most important biodiversity hotspots. 
Kwongan is the aboriginal term used for the mixed waxy leaved shrubland and heathland assemblage found in the southwest of Western Australia and South Australia around Adelaide. The Kwongan is comparable to the other types of shrubland and heathlands plant communities with a Mediterranean climate, such as South Africa’s fynbos, California’s chaparral, France’s maquis and Chile’s matorral. The Kwongan sandy soils are impoverished of nutrients and the climate, with its winter rain and summer droughts, has meant plants have evolved some extraordinary adaptations and survival tricks to cope with the difficult conditions. Theses plant communities display high levels of species diversity and a number of rare species not found anywhere else. 
There are many important plant families that make up the Kwongan, including the eucalyptus tree species from the myrtle family (Myrtaceae). However, the aim of the display is not to create a landscape dominated by these trees but to highlight some of the fascinating shrubs and subshrubs. A small winding path enables visitors to get up close and personal to some of these plants and be immersed in the wonderful fragrance emitted from the vegetation. Firstly, the Callistemon (bottle brushes) were planted from the Myrtaceae family, including the weeping bottle brush (Callistemon viminalis), a beautiful arching shrub with deep red bottle brush flowers. The name refers to the beautiful flowers, ‘calli’ coming from the Greek word meaning beautiful and ‘stemon’ meaning stamen, the male part of a flower. 
Banksia in bloom.
Photo credit: Shannon Martin
via Flickr [CC by 2.0]
The other important families for this display include the unusual plant family called the Proteaceae, which contains Banksia, Dryandra, Hakea, Isopogon and Grevillea. Many of these species are only found in the Mediterranean climatic region of Western and Southern Australia. All have exquisitely striking flowers and sculptural foliage. The Banksias are particularly interesting though. The flower heads are composed of hundreds of tiny flowers ranging in colour from yellow through to red. The fruits look like cones, with the seed encased to protect against seed eaters. These cone-like structures are what is termed serotinous where seed is let loose in response to an environmental trigger, which in Banksia’s case is fire or extreme drought. 
Other beautiful flowering shrubs that have been included in this attractive display are the kangaroo paws, Anigozanthos, whose flowers do vaguely resemble the paws of marsupials. The flowers themselves are vibrant and extremely eye-catching, held up on long tall stems to be pollinated by birds. The flower is arranged so that pollen is deposited on the heads of nectar feeding birds, with different Anigozanthos species leaving pollen on different parts of the birds’ head.
This new display has been intentionally placed adjacent to the southwestern South Africa display. The two continents were once connected forming the supercontinent Gondwana some 200 million years ago. In both countries, species from the Proteaceae and Myrtaceae are represented. This area of the garden is set to be further developed through a strategic plan to include five main plant assemblages of the Mediterranean climatic region. Three have now been accomplished. Next to look forward to are the plant assemblages from Central Chile and Western California. 
Helen Roberts is a trained landscape architect with a background in plant sciences. She is a probationary member of the Garden Media Guild and a regular contributor to the University of Bristol Botanic Garden blog.

The potential of honey: a highly topical application

Posted on by andy.winfield

By Helen Roberts

The one animal that springs to most people’s mind for eating honey is bears. Especially a particularly round individual who gets his hand stuck in the honey pot numerous times. However, many animals around the world, including raccoons, skunks, opossums and honey badgers, feast on honey. They brave the fury of the hive to not only get at the sweet sticky stuff, but for the protein obtained from eating the bees and larvae themselves. We humans are fussier and prefer to stick to just the honey, though some people will eat honey on the comb.

For centuries, honey has been recognised not only for its culinary uses but its medicinal uses, due to its antimicrobial properties. The potential scope of honey in medicine is vast and still developing despite its use since ancient times; the ancient Egyptians and Greeks commonly used honey to treat wounds. Research into the medicinal properties of honey is ongoing and not only restricted to its use in promoting wound healing, but also its potential as  an anti-inflammatory, anti-fungal, treatment for burns, aid in the treatment of chronic rhinosinusitis and combatant against the bacterial biofilms that can form in urinary catheters.

The sticky issue of Manuka honey

Manuka flowers (Leptospermum scoparium).
Photo credit: FlowerGirl on Flickr [CC BY-ND 2.0]

Manuka honey (MH) is a monofloral honey produced in New Zealand and is made exclusively by European honey bees from the flowers of the Manuka bush, Leptospermum scorparium. MH is also produced in other countries, such as Australia and even in the UK, although it could be argued that this is not the ‘real deal’, having not come from New Zealand. In fact, there is currently an acrimonious disagreement between Australian and New Zealand honey producers over the right to market MH. New Zealand producers want exclusive trademarks on MH and Australian apiarists are fighting this, arguing that MH has been used in Australia since 1831, 8 years before New Zealand even got European honey bees. The bitter battle ensues.

The ‘essence’ of Manuka honey

The unique antibacterial properties of MH are attributable to the organic compound called methylglyoxal (MGO), which comes from the conversion of dihydroxyacetone (DHA) – a simple carbohydrate that is found in the nectar of Manuka flowers. DHA is one of the markers used to grade MH on a scale known as the UMF, or Unique Manuka Factor. Manuka honey needs a minimum rating 10 UMF to be labelled as Manuka.

Microbiologist Dr Rowena Jenkins, Lecturer at Cardiff Metropolitan University, and her research team have discovered numerous health benefits of using MH, which has been supported by clinical trials. This is an opportune moment for research into non-antibiotic agents as more antibiotic resistant pathogens emerge. Jenkins and her team are particularly interested in how MH might help battle the most challenging infectious agents…the ‘superbugs’.

Meticillin-resistant Staphylococcus aureus (MRSA) is the ‘superbug’ many of us associate with health care facilities. Jenkins’ team is exploring how MH wipes out MRSA that have infected wounds sites by preventing the bacteria from dividing.  In addition, Jenkins highlighted the potential for MH to be used in combination with antibiotics to stop the growth of MRSA.

If you’re interested in learning more about the ongoing research into honey, on the 24th of August, Dr Rowena Jenkins will be a guest speaker at the University of Bristol Botanic Garden Science Picnic. Visitors can relax in the garden and engage with Rowena in an informal discussion about her ongoing research into the health benefits of honey. It’s a rare opportunity to mingle with the scientists working on the edge of cutting research. You can book your place at the University of Bristol’s online shop.

Helen Roberts is a trained landscape architect with a background in plant sciences. She is a probationary member of the Garden Media Guild and a regular contributor to the University of Bristol Botanic Garden blog.

References:

Adams, C.J., Manley-Harris, M. and Molan, P.C. 2009. The origin of methylglyoxal in New Zealand Manuka (Leptospermum scoparium) honey. Carbohydrate Research, 344(8):1050-1053.

Jenkins, R., Burton, N. and Cooper, R. 2011. Manuka honey inhibits cell division in methicillin-resistant Staphylococcus aureus. Journal of Antimicrobial Chemotherapy, 66(11): 2536-2542.

Roberts, A.E.L., Brown, H.L., Jenkins, R.E. 2015. On the antibacterial effects of Manuka honey: mechanistic insights. Research and Reports in Biology, (6): 215-224.

The pretty peony – a flower of culture

Posted on by andy.winfield

By Helen Roberts

The peony has undeniably beautiful flowers, from the perfect spherical bud giving a hint of the petal colour underneath to the rapid unfurling of immense blooms. Even the foliage is attractive, particularly towards the end of the season when they readily take on autumnal tints.

I admire them in gardens that are not my own for I have never grown peonies, the tree nor the herbaceous species. The flowers, although staggeringly large and of sublime colours and subtle scents, are too short lived for my own small garden. After all peonies need space. However, I am looking forward to the development of a new peony garden in the University of Bristol Botanic Garden. It will form part of a new ‘Culture’ display, which is being implemented this year with the help of the Chinese Garden co-ordinator, Tony Harrison, who is a traditional Chinese herbalist.

Tree peony. Image credit: RHS

Peonies are native to Asia, Southern Europe and North America and are contained within the Paeoniaceae family. There are 4 different types, the tree peony, herbaceous peony, the hybrids and the intersectional peonies, which are crosses of tree and herbaceous peonies. Tony explains the different species of tree peonies [1]:

‘When they first arrived, the Chinese tree peony was thought to be a single species which was named Paeonia suffructicosa, but research showed P. suffructicosa to be a hybrid which has been derived from at least three main species which have been interbred over several thousand years to produce the wide range of cultivars from different regions of China. These original source species were then separated into three separate wild species as P. ostii, P.jishanensis and P. yunanensis.’

A number of species will be cultivated in the new peony display at the Botanic Garden. These will include ones from different regions of China including the wild species of P. ostii, P. jishanensis and P. yunanensis as well as P. delavayi, P. rockii and P. suffructicosa, and several herbaceous species.

A long history of medicinal use

Peony tubers have been used for medicinal purposes for centuries. The bark of the roots is used to treat congestion, blood disorders and worms [2]. Tony explains the importance of peonies in Chinese medicine:

‘Peonies were being used in medicine long before they were cultivated for ornamental purposes. It is considered that peonies have been used medicinally dating back about 2,000 years. The root bark of the tree peony is used to cool and move the blood, whereas the herbaceous peony is used to tonify the blood. The Chinese name for peony is mudan (牧丹) and the characters can be translated to mean the colour “red” but also “medicine” and “healing”. The bark is separated from the remainder of the root, chopped, dried and used in combination with other substances.’

The plant is also revered for its attractiveness. The flower colours range from yellow, cream, red, pink; all the way to lavender and near black [3]. Some have a unique, almost peppery and spicy, scent. I am fond of the smell, it is not cloying or overpowering like some flower scents. The choice of peony hybrids and cultivated varieties is vast, there are so many to choose from. The herbaceous peonies are more commonly grown in Europe and North America and because of this familiarity with the herbaceous form, tree peonies are not as popular. I prefer the tree peonies as they offer interesting foliage and architectural form.

The tree peony has been grown for its flowers in China since the 6th and 7th centuries during the Sui (581-618 AD) and Tang dynasties (618-906 AD) when it appeared in the imperial palaces. It is rumoured to be one of the first flowers to be cultivated purely for its ornamental purposes from the ancient city of Luòyáng and the seat of the Sung dynasty (960-1279 AD), hence it is often called luòyànghuā or flower from Luòyáng [2]. The enthusiasm during the Sung dynasty for peonies is comparable to the tulip mania that gripped Holland in the 17th century and immense sums where paid for highly prized peonies. In Luòyáng many peony exhibitions and shows are still held there annually. Peonies in China are normally cultivated by planting in terraces or raised beds and protected from the harsh summer sun by mat awnings [2].

The symbolism of the peony

Along with many other flowers grown in China, the peony is shrouded in layers of symbolism. Among the tree peonies (Peonia suffruticosa), the male vermilion flower is known as the ‘King of Flowers’ (花王 hūawang) and represents both royalty and aristocracy [2]. The tree peony was originally grown by royalty, the aristocracy and eventually, over time, throughout China. In the imperial palaces, it was often displayed in opulent reception halls, being used as a table plant in large vases. The ink and deep red forms as well as a variety with a yellow edge on the petals, known as the ‘Golden border peony’ were highly valued [4]. The peony is also called fùguìhūa (富貴花), the flower (hūa) of wealth (fù) and rank (guì) symbolising wealth, social status and honour [2]. Despite being associated with the yang principle (male) of masculinity and brightness it also represents female beauty and reproduction, especially erotic lushness [5].

The flowers of the four seasons – the tree peony is spring.
Image: Jimmie on Flickr [CC By 2.0]

The tree peony is one of four flowers which symbolise the seasons; tree peony –  the spring (and March); the lotus – summer; the chrysanthemum – autumn; and the plum – winter.

The herbaceous peonies are termed the ‘Prime Minister of All Flowers’ and are also highly prized.
As well as using the plant form itself, peonies have long been depicted in Chinese art forms (literary and visual) for centuries and they form one of the main motifs in silk tapestries, paintings, lacquerware and clothing. They are often displayed alongside peacock, pheasant, fowl, phoenix and lion to represent splendour, status and nobility [2].

Such is the importance of peonies in Chinese culture that numerous stories and poems have been written and told. There is the wonderful fable of ‘The Fabulous Peony’, where the wicked and vain Empress Wu Zetian ordered all flowers in the Imperial garden to bloom overnight in winter and those that did not would be punished. The senior member of the Imperial garden, the Male Vermillion Peony refused to obey, whilst the other flowers in the garden submitted and duly produced blooms to please Empress Wu.

In her fury at being disobeyed, the peony was banished from the Imperial Palace and anyone growing it would be put to death. To save the peony from destruction the royal gardener, Pei Fu sent roots of the peony to a friend in Luoyang, a place considered lacking in culture and hence not likely a place to arouse suspicion. And here the peony flourished, the peony gardens at Luoyang remaining a secret until the death of the Empress Wu when it emerged out of hiding [6].

Helen Roberts is a trained landscape architect with a background in plant sciences. She is a probationary member of the Garden Media Guild and a regular contributor to the University of Bristol Botanic Garden blog.

References:

[1] Harrison, T. Varieties of Peony. Journal Archive. The Register of Chinese Herbal Medicine.
[2] Williams, C.A.S., 2006. Chinese Symbolism and Art Motifs: A Comprehensive Handbook on Symbolism in Chinese Art Through the Ages. Tuttle Publishing.
[3] Fearnley-Whittingstall, J., 1999. Peonies. Harry N. Abrams.
[4] Li, H.L., 2012. Chinese flower arrangement. Courier Corporation.
[5] Welch, P.B., 2013. Chinese art: A guide to motifs and visual imagery. Tuttle Publishing.
[6] Chew, K., 2008. The Magical Dumplings and Other Chinese Fables. iUniverse.

‘Tis the season…or is it?

Posted on by andy.winfield

By Helen Roberts

As I sit at my desk this morning, staring out the window, the weather is dire. There is slanting torrential rain and high winds, a typical December day perhaps.
Here in the UK, the seasons are changing and we are experiencing extremes of weather. For example, we have had wetter, milder winters in the southwest over the last couple of years along with increased flooding, particularly on the Somerset Levels. And then there was the very slow start to spring this year, with temperatures well below average in April. This was followed by a very hot end to the summer and warmer-than-average temperatures throughout autumn.
These changes to the seasons are linked to global climate change and are throwing the UK’s wildlife into disorder and affecting the fine balance of habitats and ecosystems. This is not a good scenario for biodiversity in the UK. Seasonal timing is off. When seasons start and end is shifting, and the length of the season itself is changing, making ‘growing seasons’ a more fluid concept. There is also increased risk for most gardeners of a ‘false spring’. Many plants and animals are changing their geographical ranges in order to adapt to these changes.
One of the most significant effects has been the disruption of lifecycle events and these are manifesting themselves in different ways. Bird migration, insect emergence, incidence of pests and diseases and flowering times are being thrown out of kilter.  
Researchers from the University of East Anglia recently analysed 37 years worth of data from the UK Butterfly MonitoringScheme (UKBMS) and found that extreme weather events were causing population crashes of butterflies. Uncommonly high rainfall events during the cocoon life stage affected 25% of UK butterfly species. And more than half of species were affected by extreme-heat during the overwintering life stage, possibly due to the increased incidence of disease or the effect of a ‘false spring’, causing butterflies to emerge too early only to be decimated by a return to cooler temperatures.
Warm temperatures are not all bad for butterflies though, as they will benefit from hot temperatures over the summer months when they are in their adult form and resources are plentiful. However, if populations crash more frequently than they expand, these extreme weather events could threaten UK butterflies.
The spider orchid (Ophrys sphegodes).
Photo: Jacinta Iluch Valero via Flickr [Creative Commons]

Changes in seasonal timing are also knocking the relationships between plants and animals out of sync, including the delicate balance between plants and pollinators. Thiscan be detrimental to the balance of entire ecosystems. An elegant study carried out by scientists from Kew and the University of East Anglia found that earlier springs brought about by rising temperatures are affecting the relationship between a rare spider orchid (Ophrys sphegodes) and its sole pollinator, the solitary miner bee (Andrena nigroaenea).   

This particular orchid has a flower that resembles and smells like a female miner bee and it uses this deceit in order to lure the male miner bee in. The male attempts to mate with the flower and by doing so, pollinates the flower. The plant has evolved to flower at the same time as the male bees emerge, but before the females do.
What the researchers discovered, by looking at the data set going back to 1848, was that rising temperatures are causing the relationship between orchid and bee to break down. Although rising temperatures cause both the bee to emerge and the orchid to flower earlier, the effect on the bees is much more pronounced. The male bees emerge much earlier and the orchids now flower as the female bees emerge. This means the males are not “pseudocopulating” with the flower because the real thing is already available and so the rare spider orchid is having fewer pollinations.
However bleak this picture may seem, plants and animals do have the ability to adjust to seasonal changes caused by climate change, it is just whether they can adapt quickly enough for these intricate ecological relationships to remain intact.
Helen Roberts is a trained landscape architect with a background in plant sciences. She is a probationary member of the Garden Media Guild and a regular contributor to the University of Bristol Botanic Garden blog.


References

The evolution of a predatory plant

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By Nicola Temple

We keep a Venus flytrap (Dionaea muscipula) in our bathroom. My son begged me for it, which inevitably means I look after it. Having seen these carnivorous little delights in the glasshouses at the University of Bristol Botanic Garden, I have learned that humidity and moisture are key to its happiness – hence it’s bathroom location and its constant immersion in a tray of water.

The leaves of  the Venus flytrap, open (foreground) and
wrapped around its prey (background, right).
Photo credit: Shelby Temple
While I mostly leave my son to do the part he loves best – feeding – I can’t deny my own fascination with it. The leaves, converted to ambush traps through evolution, have to have enough stimulation by an unsuspecting insect to warrant the plant investing the energy to snap the trap shut.  Once the trap is shut, the plant estimates the size of the prey based on the amount of stimulation of the sensory ‘hairs’ triggered by the trapped (and no doubt panicked) insect. If there is a sufficient signal from the sensory hairs, the plant starts to produce enzymes and proteins that will help it digest and absorb the prey. It’s the stuff of nightmares…for the insect.
So what evolutionary steps transformed a leaf designed to harvest light from the sun into a leaf designed to trap prey? New research published this week in the journal Genome Researchhas provided some insight into the origins of the Venus flytrap’s trap.

It’s a leaf with a hint of root and a dash of…tongue?

Professors Rainer Hendrich and Jörg Schultz led a team of scientists from Julius-Maximilians-Universität Wüuzburg (JMU) in Bavaria, Germany who looked at the genes being expressed by the traps. They found that the traps not only had active genes typical of leaves, but also those typically found in roots.
A close up view of the trap, which shows the sensory ‘hairs’.
Photo credit: Shelby Temple
There are dome-shaped glands on the surface of the trap. The outer layer of each gland secretes the digestive enzymes, but the middle layer has foldings that increase the surface area – reminiscent of microvilli in the human intestine. It is thought that this is where nutrient absorption takes place. As this is a major function of roots, it is not surprising that some of the same genes are required.
Now…about about that tongue. I mentioned above that the plant releases digestive enzymes if it receives enough stimulation within the closed trap. But what if the insect dies very quickly after being trapped? The plant has a receptor in the trap that can detect chitin – the main constituent of an insect’s exoskeleton.  So even if the insect is no longer moving, the plant can ‘taste’ the insect in the trap and begin digesting.


Switching from defence to offence

When non-carnivorous plants come into contact with chitin, it is usually not going to turn out well for the plant –  they are under attack by herbivorous insects. Henrich and Schultz looked at the defence mechanism triggered by insects feeding on the non-carnivorous plant thale cress (Arabidopsis thaliana). They found that the plant in defence mode activates the same genes in the same pattern as the Venus flytrap in attack mode.
“In the Venus flytrap these defensive processes have been reprogrammed during evolution. The plant now uses them to eat insects,” explains Hedrich.
In both cases, mechanical stimulation (whether a chewing insect or a trapped one) generates an electrical impulse that activates the release of the hormone jasmonate. In Arabidopsisthis hormone begins a cascade of events that starts the production of various chemicals that deter the insect or make the leaves hard to digest. In the Venus flytrap, however, jasmonate starts the digestion of the insect and uptake of the nutrients.
So, the ancestor of the Venus flytrap had all the machinery in place for detecting insects and triggering a chemical response to their presence, but evolution managed to shift it from a defensive strategy to a very effective offence.

Source: 

“Venus flytrap carnivorous life style builds on herbivore defense strategies”, Felix Bemm, Dirk Becker, Christina Larisch, Ines Kreuzer, Maria Escalante-Perez, Waltraud X. Schulze, Markus Ankenbrand, Anna-Lena Keller Van der Weyer, Elzbieta Krol, Khaled A. Al-Rasheid, Axel Mithöfer, Andreas P. Weber, Jörg Schultz, Rainer Hedrich. Genome Research, DOI: 10.1101/gr.202200.115

Bristol is buzzing, how the city is helping pollinators

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By Helen Roberts

There has been a substantial amount of press coverage recently on the plight of our pollinators. They are now less abundant and widespread than they were in the 1950s. A number of threats are responsible, including habitat loss, disease, extreme weather, climate change and pesticide use.
A swathe of flowers for pollinators bring a
lot of cheeriness on a grey autumn day on
Horfield Common, Bristol.
Photo credit: Nicola Temple
There is not one smoking gun among these threats, but rather the combination that has endangered some species in the UK. Loss of wild flower rich habitat (due to intensive agriculture, industrialisation and urbanisation) escalates the effect of disease, extreme weather, climate change and pesticide use. Without food or shelter, pollinators are more vulnerable.

 Whilst visiting the University of Bristol Botanic Garden this autumn, I noticed the abundance of pollinators busily visiting many different flowers from the orchid look-a-like flower of Impatiens tinctoria to the swathes of Rudbeckia sp. and Verbena bonariensis. This year saw the 6th year of the University of Bristol Botanic Garden hosting the Bee and Pollination Festival in September. The Community Ecology Group from Bristol’s School of Biological Sciences was exhibiting and promoting their research as well as the exciting Get Bristol Buzzing initiative.
To find out more about pollinator research at the University, I met up with Dr Katherine Baldock, a Natural Environment Research Council Knowledge Exchange Fellow from the School of Biological Sciences and the Cabot Institute, to discuss the group’s work.
“Most people know that pollinators are important, but quite often don’t know what to do to help them, “ explained Katherine. “And this is where our research at the University comes into play”.
The aim of Katherine’s fellowship is to improve the value of the UK’s urban areas for pollinators by working with various stakeholders, such as city councils, conservation practitioners and the landscape industry. 

Translating science into solutions

NERC KE Fellow Dr Katherine Baldock.
Photo credit: Nicola Temple.

Up until 2014, Katherine worked on the Urban PollinatorsProject, which is researching insect pollinators and the plants they forage on in urban habitats.
Building upon research from this project and her current Fellowship, Katherine and her Bristol colleagues have contributed to the development of  a Greater Bristol Pollinator Strategy(2015-2020). The University research group has teamed up with Bristol CityCouncil, the Avon Wildlife Trust, Friends of the Earth Bristol, Buglife, SouthGloucestershire Council and the University of the West of England to implement this with the aim of protecting existing habitat and increasing pollinator habitat in the Greater Bristol area.
The group is also raising awareness of the importance of pollinators to a wide-ranging audience within the city and further afield. This is the first local pollinator strategy within the UK and follows closely in the wake of the Department for Environment, Food and Rural Affairs’ National Pollinator Strategy launched in 2014. It will help to promote aspects of the national strategy relevant to urban areas and hopefully set a precedent for the development of other local pollinator strategies throughout the UK.
The local pollinator strategy outlines actions that will help fulfill the strategy aims, including:
·         formation of a Local Pollinator Forum intended to share knowledge and best practice,
·         establishment of a joined-up approach to pollinator conservation by linking projects through the Get Bristol Buzzing initiative,
·         working with the public in local areas to explain actions they can take as individuals.
“Urban green spaces are important corridors for wildlife and help to provide linkages across the country”, explained Katherine. I envisaged a series of insect aerial motorways linking the whole of the UK, invisible threads connecting countryside, urban fringe and city centres.

The bee link-up

The Get Bristol Buzzing initiative is doing just that, as one of its strategic aims with the local pollinator strategy for 2016-2020, is to “Map pollinator habitat and identify target sites that allow habitat networks and stepping stones to be created to enable pollinators to move through urban areas”.
Katherine talked about how engaging the public at ground level was really important to Get Bristol Buzzing. The initiative is the pollinator component of My Wild City, a project whose vision is for people in Bristol to help transform spaces into a city-wide nature reserve. A number of interactive maps have been created that allow people to add what they have been doing in their area to help wildlife. The Get Buzzing initiative will feed into these maps.
Kath said, “The fact that you can add yourselves onto a map makes the Get Buzzing Initiative really visually appealing to people and much more personal.”

So, what can you do at home to help urban pollinators?

·         Plant for pollinators. Think about what plants you have in your garden. Could you change the planting or improve on it to make it more attractive to pollinators? Think about growing species that have nectar and pollen rich flowers and let your lawn grow longer to allow plants to flower.
·         Avoid pesticides. Most gardeners like their plants to remain pest free but avoid the temptation to use pesticides and accept the fact that you will lose some plants to pests. Instead try to encourage wildlife that will devour those pests or cultivate plants that will deter pests. 
·         Provide habitat. As pollinators need a home, you can always make your own nest boxes if you want to give your pollinating visitors a helping hand by drilling holes in a log or by bundling up lengths of hollow sticks such as bamboo. Visit the Botanic Garden’s bee hotel for inspiration!
“Setting aside a wild bit of garden can help pollinators by providing food, but provides nesting sites too”, remarked Katherine.

Additional information:

·         The Urban Pollinators Project was recently listed as one of the top 10 ground-breaking research projects in the Daily Telegraph. Read more.

·         Results from this research have recently been published in the Proceedings of the Royal Society B with more publications in press. A list of publications can be found here.

·         You can read more about Dr Katherine Baldock and the Urban Pollinators Project on page 7 of the 2015 edition of the Cabot Institute’s magazine.

Undergraduates get their first glimpse at the garden

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By Alida Robey

I’ve been promising myself a visit to the University of Bristol Botanic Garden since I arrived in Bristol four years ago. Life has intervened. Yet when the opportunity came to join the new intake of students from the University on their first practical of their 3 year undergraduate degree, I leapt at the chance. 
Once there, the thrill of the plants, garden, stories and mysteries within, were hard to resist!  I joined the briefing given by the Garden’s curator, Nick Wray, as he introduced the day’s second group of 70 students (over 250 students attended the practical over two days) to their PhD student demonstrators – there to inspire the undergraduates about different aspects of the gardens.  

An introduction to the day

These biology and zoology students were visiting the garden as part of their ‘Diversity of Life’ module – taking a first-hand look at some of the adaptations that have enabled plants to diversify into the more than 400,000 species that exist today. Beyond this, however, the practical offers an opportunity for the students to get to know each other and learn to work collaboratively, gain confidence in sharing knowledge,  as well as orientate themselves to this incredible resource available to them.
Nick and the demonstrators were up against time and the logistics of manoeuvring 70 students around 6 ‘work stations’. Students were split into manageable groups and two volunteer guides were brought in to assist moving the groups swiftly through the rotation of topics presented around the garden.
Off we went. As a newcomer myself, I shared the sense of wonderment and awe one student expressed as she exclaimed at how much more there was at the Garden than she had expected. She pointed out how interestingly organised the gardens were, which effectively revealed the story of plant evolution – a set-up that Nick had explained was unique to the University of Bristol Botanic Garden.

Into the glasshouses for plants that eat and are eaten

I followed a group into the glasshouses where Edith showed us the adaptations plants have evolved to cope with extreme habitats. Plants from very different families share common features that are adaptive in similar conditions. Euphorbia, for example, which grows in the deserts of Africa is so similar to the form of cacti found in the deserts of America that they are often misidentified – this is an example of convergent evolution.
The striking Haemanthus coccineus – a native of South Africa -flowers and then sets seed in autumn to coincide with the first rains, giving the seedlings a full rainy season to develop. The leaves appear well after the flowers to reduce the amount of moisture lost prior to the rains. Edith pointed out carnivorous plants that have adapted to nutrient poor habitats. She showed us a plant that produces citronella to deter insects and a species that looked half eaten to make it less attractive to herbivores.
The group was then passed along to Nick who ushered us into the tropical greenhouse to reveal further wonders, such as the orchids of Mexico that require pollination by moths to produce vanilla pods. When commercially produced in the Comoros Islands, pollination is done by hand for every flower – a task often given to children in this struggling economy. We saw the giant lily pads of Victoria cruziana. Reminiscent of triffids, Nick pointed out that in summer they have to be cut back every three days to prevent them growing out of the pond.
Nick Wray shows the students the largest seed in the world.
Photo credit: Nicola Temple

Hmmm… time to escape back into the fresh air where things were growing at a more manageable pace for me, but Nick continued to show the group other commercially important plants, such as lotus, bananas and cotton. He held up a specimen of the world’s largest seed – that of the sea coconut or coco de mer (Lodoicea maldivica), which can weigh up to 30 kg.

The students were then taken into an area of the glasshouses that’s not open to the public and shown some very rare and unique plants, including Amborella trichopoda, which is of particular interest because molecular analyses suggest this is one of the earliest flowering plants. It is the last remaining species of a group that first appeared on Earth more than 140 million years ago, when dinosaurs still dominated the animal kingdom.  A sprawling shrub native to New Caledonia, Amborelladoesn’t cope with changes in humidity very well, so it is kept behind plastic to control the humidity.
Some students scribbled madly, while others just chose to listen as Nick enthusiastically explained what a unique experience this is for University of Bristol students.  ‘Until last year, Bristol was the only botanic garden in the UK growing this plant,’ said Nick. (The University of Cambridge has recently acquired one.)

New Zealand garden – survival of the species

In the New Zealand garden, Dave showed the radical ways plants survive difficult conditions; in this case, the attentions of the now extinct Moa bird. This was graphically illustrated by Pseudopanax, which starts off its first 10 years or so as a sapling with hard, spiky, downward facing sword-like leaves. Once considerably taller – namely beyond the reach of 3m tall Moas – the trees don’t invest as much energy into being unpalatable and transform into an unrecognisably different form, with soft and safely inaccessible leaves reaching to the light.

Angiosperm phylogeny explained

A group gathers around the pond to learn about angiosperm
phylogeny. Photo credit: Nicola Temple

I moved on to hear about angiosperm phylogeny; a new term for me, but more exciting and less daunting than it sounds. In the past, plants were classified into family groupings based on their physical characteristics. With the advent of DNA sequencing in the last 20 years, we can use genetic relatedness to help us understand how plants have evolved. James, our demonstrator, pointed out some of the oldest species of flowering plants, including star anise (Illicium verum). This area of the garden is organised into the two major groups of flowering plants monocotyledons (seed has single embryonic leaf) and dicotyledons (seed with two embryonic leaves). The monocots include plants such as orchids and grasses, including agriculturally important species such as rice, wheat, barley and sugar cane. The more familiar garden plants, shrubs and trees, and broad-leafed flowering plants such as magnolias, roses, geraniums, and hollyhocks are dicots.

Learning in the garden beats a textbook any day

Speaking with the students, they said they enjoyed being able to touch and feel the actual plants, make comparisons and learn within this physical context. They could see as James explained how even though Protea, lotus, Banksia and London plane tree (Platanus x acerifolia) looked very different, their DNA suggests they are more closely related than they appear. Genetic relatedness is traditionally illustrated using a cladogram – a branching tree with scientific names at the end of the branches, with no sense of what these species look like. What an opportunity to see what the diversity at the end of those branches can look like!
Students use pens to see how flowers are
adapted to distribute pollen on the
pollinators that visit them.
Photo credit: Nicola Temple

My time ran out before I could get as far as the sessions on pollination and plant evolution!  With my head spinning from this intensive and whistle-stop tour of some of the delights and extraordinary features of this garden, I sat on a bench in the autumn sunlight to reflect on the afternoon with fellow blogger, Nicola Temple, who had invited me take part in this day.

Like many of the students I spoke with as we went from location to location, I was delighted to have had the opportunity to understand the great thought behind the layout of the gardens.  There was far and away more here than I had bargained on.  I wanted to keep going but knew I could only take in so much on my first visit.  As we had gone around I had been surprised as an observer to note how quiet the students were, very few asking any questions.  Having stood back from it though I wonder if, like me, they were overwhelmed by the hidden depths to this exceptional garden. I’m certainly going to seek every opportunity to spend more time here, whether learning or simply enjoying the peaceful and stunning surroundings.
And I daresay I will come across many of the students from this day, pursuing their studies and enjoying the sheer delight and boundless wonderment that nature continues to shower upon us and that this garden so beautifully illustrates.

Latecomers to the summer flowering party

Posted on by andy.winfield

By Helen Roberts

It’s the time of year when most people think that gardens are nearing the end of the full flush of summer blooms. Mid summer flowers may be dwindling but there are numerous late flowering species that still provide a riot of colour. I have always been interested in gardens at this time of year because we are often rewarded with a spell of bright sunny weather in autumn. I want to be outside enjoying the garden, hanging onto the summer for as long as I can before the cold deepens and the nights draw in. So planning for some autumn colour in the garden can be very rewarding.
  
With thoughts of designing my own garden for a prolonged season of flowering, an excursion to the University of Bristol Botanic Garden was due. I met up with Froggie who showed me the bounty of colour at this time of year in the gardens.
First stop was the hot borders which can be found in front of The Holmes, which were evidently at their most scorching in terms of vivid colours, with swathes of Hemerocallis, Penstemon, Helenium, Rudbeckia, Tithonia, Fuchsia and Dahlia. Froggie pointed out the lovely Verbena bonariensis, which is such a great plant for pollinators and one that self seeds profusely. Verbena adds some soft architectural form to borders and provides flowers for months on end. A plant that I was less familiar with was the rather cute and tender Cuphea cyanea or Cigar flower with red and yellow tipped flowers. There is also another variety of Cuphea called the Pink Mouse – each flower does look like a miniscule mouse!
Providing structure to the hot borders were the awesome sub tropical Abyssinian Banana (Ensete ventricosum), which were still looking amazing but will soon be lifted and taken into the greenhouses. The staff keep a close eye on the weather at this time of year, any sign of frost forecast and they must move quickly to take in the tender species.
Froggie explained, “We had some hard winters a few years back and we lost quite a lot of plants so lifting plants into the greenhouses ensures they are protected. They are our insurance against a very cold winter.”
Salvia uliginosa can be found flowering this time of year
by the Botanic Garden’s main pond.
Photo credit: Helen Roberts.
Many of the shrubby salvias are in this tender category. Froggie showed me Salvia confertiflora, an exotic late flowering species with beautiful fuzzy crimson inflorescences about 0.5m tall. This will be moved inside soon when the weather cools. Another that caught my eye in the pollinator beds located on one side of the main pond was Salvia uliginosa, a very tall plant with vibrant sky blue inflorescences that were buzzing with bumblebees.
I have to admit to an obsession with shrubby salvias, which started after many visits to the garden of plant guru Derry Watkins over the course of this summer. Her passion for these beautiful plants is contagious. They are an extraordinary group of plants that flower continuously from June until October and the flower colours are exquisite. The colours really pack a punch in terms of vividness. I purchased Salvia microphylla ‘Cerro Potosi’, which started producing vibrant magenta flowers back in June and is still putting on a show of pink in October. I plan to take cuttings of this to provide a back up plan in case I lose my original plant (I am going to risk leaving mine out over winter).
Toad Lilies (Tricyrtis macropoda). Photo credit: Helen Roberts.
In amongst the buzzing pollinator borders were the very pretty and delicate Toad Lilies (Tricyrtis macropoda). I watched bees visiting these inflorescences and collecting nectar by robbing it through the back of the flowers. The pink flowered society garlic (Tulbaghia violacea) and Japanese Anemone (Anemone hupehensis) were very subtle in hue combined with dazzling yellow Rudbeckia and deep purple drooping flowers of Agapanthus inapertus ‘Midnight Cascade’. Many of the hummingbird-pollinated plants were in flower including the pineapple relative Ochagavia litoralis and the terrestrial bromeliad Fascicularia pitcairnifolia. The latter, at present, is visually screaming, “Come pollinate me!” with the centre of the rosette turning an intense scarlet with a dense cluster of blue flowers tipped with bright yellow pollen.
Throughout the gardens, as I toured around with Froggie, there were interesting flowering species and the colours varied tremendously from vivid red and pink to deepest indigo. The flower forms were diverse too; delicate dangling umbels, ‘in your face’ discs of blooms, hooked and lipped nectar-rich inflorescences and some which were just plain weird looking. The gardens simply still looked stunning and I left knowing that it’s not yet time to put gardens to bed, there’s plenty more flowers to come.
More species that are flowering now in the garden include:
  • Abutilon sp. (Chinese lantern)
  • Agastache sp. (Giant hyssop)
  • Campsis sp. (Trumpet vine)
  • Caryopteris x clandonensis (Bluebeard)
  • Colchicum agrippinum
  • Commelina tuberosa Coelestis Group (Day flower or Sleeping Beauty)
  • Crinodendron hookerianum (Chilean lantern tree)
  • Erica tetralix (Cross-leaved heath)
  • Impatiens tinctoria
  • Lantana camara (Yellow sage)
  • Liriope muscari (Big blue lily turf)
  • Tropaeolum peregrinum (Canary creeper)
  • Verbena peruviana (Peruvian verbena)

A walk through the mendips

Posted on by andy.winfield

By Helen Roberts

A few weeks ago our family, had a great day out walking on the Mendip Hills. We set off in autumn sunshine, through pretty deciduous woodland, to an Iron Age hill fort called Dolebury Warren – an upland area of calcareous grassland. Having lived on the edge of the Mendips during my childhood, I am always keen to show my children where I used to explore as a youngster.
Part of Cheddar Gorge, Somerset, England, seen from a
light aircraft. Photo by Adrian Pingstone (1975).
The Mendips are a range of mainly carboniferous limestone hills comprised of at least four convex fold structures formed between 363 and 325 million years ago, during the end of the Carboniferous Period. Weathering of the limestone has resulted in features including gorges, dry valleys, screes and swallets (sink-holes) and incorporates the famous Cheddar Gorge and Burrington Combe, each with extensive cave systems. The area also has interesting landscape characteristics like limestone pavements and other karst structures.
The geology of the Mendips makes for interesting ecological communities and consists of large areas of open calcareous grassland with many rare flowering plants. For instance, Dolebury Warren owned by the National Trust and managed by Avon Wildlife Trust, sits within the Mendip Hills Area of Outstanding Natural Beauty and is a Site of Special Scientific Interest due to its important limestone flower communities. These flower communities attract up to 70% of all British butterfly species. Dolebury Warren has a gradation of communities from species rich calcareous grassland, through acid grassland to limestone heathland, with large areas of mixed scrub.
Cheddar Pink (Dianthus gratianopolitanus).
Photo by Paul Harvey, via Wikimedia Commons
The charity Plantlife has identified the Mendips as an Important Plant Area (IPA), which is an area of landscape that has very high botanical importance. Some plant species found on the Mendips are found nowhere else. Due to factors such as over grazing, poor land management, scrub encroachment and agricultural intensification, these plants are declining in numbers and some are threatened with extinction. The University of Bristol Botanic Gardenhas a local flora and rare native plant collection, which includes a sub-collection from the Mendip Hills, Limestone Cliffs and Coastal Islands. The collection was developed to help grow and interpret some of the rare and threatened plant species found in these habitats. The collection represents an important habitat and phytogeographic display and is helping meet the objectives of the ‘Global Strategy forPlant Conservation’.

Rare plants of the Mendips 


One of the Mendip plants in the Botanic Garden’s collection is the Cheddar Pink (Dianthus gratianopolitanus). This is a very pretty scented pink flower that grows in a few places on the Mendips but mostly at the original site of Cheddar Gorge. This plant was originally discovered about 300 years ago and is considered the pride of Somerset and was voted the County Flower. It grows best in rock crevices, high on the limestone crags of the Gorge, and can be seen in June and July using binoculars to search patches of colour visible on the cliffs, just above the road.
Also growing at the Gardens is the interestingly named Starved Sedge (Carex depauperata). This is an exceptionally endangered plant that is only found in one local area – in the woods and on a hedge bank near the small town of Axbridge. This is one of only two sites in the whole of the UK. Fifteen years ago, Starved Sedge had declined to such an extent that there was only one plant in the whole of Britain. As appearances go, it’s not much to look at. It’s a tussocky plant with trailing leaves and gigantic seeds and can easily be mistaken for some common woodland grasses. A reintroduction programme has improved the status of this plant by using cuttings and seed collecting to re-establish it at other sites in the UK.
The University Botanic Garden are also helping to preserve another plant at high risk of extinction and classed as nationally rare, known as Somerset Hair-grass (Koeleria vallesiana). Again, this is a fairly innocuous grass restricted to the Mendip Hills with very slow spreading habit. The Bristol Botanic Garden’s specimens were collected from Brean Down, which is the most westerly part of the Mendip Hills, as well as the interesting tiny islands of Steep Holm and Flat Holm.
Brean Down is an outstanding example of calcareous grassland and supports endemic plant communities that provide for many important insect communities. Other important plant species growing at Brean Down and now growing at Bristol Botanic Gardens include the White Rockrose (Helianthemum appenninum). This is an attractive white flowered perennial sub shrub, which frequently grows on southern slopes. White Rockrose, Somerset Hair-grass and Dwarf Sedge (Carex humilis) are all particularly at risk due to scrub colonization. This highlights the importance of grazing to maintain grassland habitats. The National Trust introduced grazing by long horned White Park Cattle and British WhiteCattle (feral goats are already on Brean Down) to help keep the grass short and scrub species controlled. 
The rarity of the plants found on the Mendip Hills highlights how important collections, such as those held at the University Botanic Garden, are for ensuring the survival of plants teetering on the brink of extinction. Equivalent to a botanical savings account, these collections help ensure that if plant species are lost, they can be reintroduced back into the wild.