Author: andy.winfield

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.

Walking among bees with Steven Falk

Posted on by andy.winfield

By Nicola Temple

Steven speaking to us in front of the limestone
meadow. Photo: Nicola Temple
I thoroughly love watching insects visit my garden (aphids and a few other pests excepted). However, I have to admit that beyond broad groupings, bumblebee, honey bee, hover fly, fly etc, I’m not very good at identifying them down to species. This clearly isn’t necessary to enjoy them, but I do find that when I know a species, when I know its routines and habits (as much as anyone does), then I have a deeper appreciation for them. So, when the University of Bristol Botanic Garden offered a bee identification workshop with Steven Falk, I signed myself up.
Steven Falkhas had an interest in insects since his childhood in London in the 1960s and 70s. Insects inspired his artwork and his skill as an artist earned him the honour of illustrating the book British Hoverflies, which he began working on when he was only 15. He has gone on to illustrate and write many publications since, including my newly acquired Field Guide to the Bees of Great Britain and Ireland (Bloomsbury, 2015).
Steven began the talk with some fast facts about insects in England. There are about 24,000 species of insect in England, 6,000 of which are regular visitors to flowers. “The biggest slice of this insect pie is wasps,” he explained. Even parasitic wasps visit flowers, and all together there are around 2,800 species.  Bees make up a mere 280 species and hover flies another 280. However, though they are less diverse in terms of species, bees and hoverflies are both abundant and extremely effective pollinators – so they punch above their diversity, so to speak.
Steven holding a yellow-legged mining-bee.
Photo: Nicola Temple
We start our walk in the Botanic Garden in the limestone meadow, just beside the West Terrace and the pond. If you unfocus your eyes a little and stare across the flowers, it is alive with activity. Steven shows us Myathropa florea, a reasonably sized hoverfly that has distinct grey markings on its thorax. It has an aqueous larvae, which lives in little rot holes at the base of trees. Then Steven points out a bumblebee mimic, Cheilosia illustrata, which tends to spend time near Hogweed because its larvae tunnel through the stems and roots. Apparently you can tell the age of a forest by the species of hoverfly present because they are so closely associated with certain plants.
Within minutes we’ve also spotted a common carder-bee (Bombus pascuorum) with its chestnut thorax – though Steven explains that this can be quite variable. It has a longer tongue and so this species is able to get down into the clover flowers. But there are also some buff-tailed bumblebees (Bombus terrestris) flying about also, which have shorter tongues and so they bite a hole at the base of the flower to rob the nectar. We spot lots of honey bees (Apis mellifera), which Steven also explains can be extremely variable in appearance, ranging from the typical striped appearance to almost entirely black – the tell tale sign being that its hind legs hang down as it flies. We haven’t even moved on the tour and we’ve already spotted at least six pollinator species – probably far more, I just can’t write fast enough to keep up with Steven listing them off!
The ‘fuzz’ of lamb’s ear is used by the female
wool-carder bee to line her nest.
Photo: Nicola Temple
Using what he calls his ‘praying mantis’ technique, Steven grabs a yellow-legged mining-bee (Andrena flavipes), and holds it so that we can all have a look at it. The long antennae tell you that this is not a fly, however, Steven goes on to list the colour variations that you can encounter. With all of these colour variations, I’m pretty sure I don’t stand a chance of accurately identifying anything on my own!
As we wander past some Lamb’s ear (Stachys byzantina), Steven mentions that the female wool-carder bee (Anthidium manicatum), a solitary bee, uses the fuzz from the plant’s leaves to line its nest. Steven then spots a patchwork leaf-cutter bee (Megachile centuncularis) and explains that it doesn’t collect pollen on its hind legs, but rather on its underbelly. Using his insect net, he catches it and place it temporarily in a little tube so that we all get a chance to look at it.
We walk past the wall germander (Teucrium chamaedrys) and there doesn’t appear to be a single flower that isn’t being visited by a bumblebee. It becomes obvious that while many of the tour participants are interested in the bees, they are equally interested in noting down which of the plants in the Botanic Garden are popular with pollinators so that they can create more bee-friendly gardens at home.
A great pied hoverfly (Volucella
pellucens).
Photo: Nicola Temple
As one would expect, near the end of the tour Steven begins to discuss some of the challenges that our pollinators face these days. He discusses the use of pesticides and the loss of habitat. He mentions that more erratic weather patterns and mild winters can lead to mortality – the latter causing over-wintering bees to go mouldy. But, he also finds the silver lining, stating that some bee species are expanding their distribution due to climate change.
It was only the commitment to another tour that forced Steven to end our walk. His love and enthusiasm for insects was apparent and he could have no doubt gone on to discuss far more than he did.
I definitely had different expectations for the workshop. I’m not sure whether it was the term ‘workshop’ or my own background in biological sciences that set my expectations that we would be looking at example specimens and comparing their features so that we might be able to better identify them. This was more of a garden tour and pollinator walk, which was lovely, but I’m not entirely sure I feel better equipped to identify bees in my garden as a result of being on the tour. If anything, it has shown me how much variation there can be within species let along adding in mimics and related species into the mix!  In the end I bought the Field Guide because really, in the end, that’s what it takes…good ol’ practice! And if I’m unsure Steven said to send him a picture on Twitter and he’ll help me identify it, which is brilliant! Not to mention, he has a fantastic free site on Flickr with pictures and information about all the British species, which is an incredible resource.
Germander (Teucrium chamaedrys) attracts
a tremendous number of pollinators.
Photo: Nicola Temple
This is the Year of the Pollinator at the Botanic Garden, so there are any number of pollination themed activities happening this year, including a beekeeping taster day, short courses for encouraging pollinators to your garden, and of course the annual bee and pollination festival in September.  And if you happen to snap a great photo of a pollinator this summer, you can enter the Botanic Garden’s photography competition, which will earn you a signed copy of Steven’s Field Guide to the Bees of Great Britain and Ireland as well as tickets to the Bee and Pollination Festival, visit the website for more details on how to enter.

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.

Beauty in Nature, Nature in Beauty

Posted on by andy.winfield

The 2017 University of Bristol Botanic Garden Sculpture Festival and Quilting Exhibition

By Alida Robey

Plant holder by Willa Ashworth.
Photo credit: Alida Robey

I have to confess that my expectations were low when I entered the University of Bristol Botanic Garden on Easter weekend to explore the sculpture festival. I have been to a few of these types of events over the years, none of which have done much to enhance either the setting or the ‘nicknacks’, described as art, on display.  I tend to favour simple uncluttered  gardens, focused on plants. My preconceived ideas were soon turned on their head, however, by the huge crowds queuing to get in and people milling about happily in the gardens. The right balance had been beautifully struck between fine art and very accessibly ‘buyable’ items. 

This year’s festival was the busiest yet with a record 4,729 people coming through; this annual Easter weekend event has been gaining in popularity with 2,459 people in 2013, 2,889 in 2014, 3,156 in 2015 and 3,161 in 2016. The exhibition effectively showcased the art, while at the same time drawing people through the various garden displays, with works of art that were well suited to each of the distinct areas of garden.
Large flame scallop by Philippa Macarthur.
Photo credit: Alida Robey
I spoke to several people who were all warmly enthusiastic about the whole event; helped by good weather, these visitors said they had enjoyed the atmosphere of bubbling positivity, been impressed with the creativity on display, and were thoroughly delighted in wandering through the gardens enjoying the new life bursting into leaf and flower. It was an all-round good day for people of all ages. 
I had seen a few people walking away clutching items of garden art that they had purchased.  Talking to some of the traders there, it was apparent that this had been a great success from their point of view too.  They loved being in the beautiful setting, had enjoyed seeing how the gardens had developed since previous years and were pleased at the response they had had from visitors who, if they hadn’t made purchases, often went off with contact details to follow up on at a later date.
Dish by glass artist Adele Christensen.
Photo credit: Alida Robey
One could not do justice here in print to the range and diversity of work on display. From the large shallow dishes made by Adele Christensen (see photos) with their lustrous and mysterious finish, looking like something you might find in a magical rockpool, reflecting sky and water. To the silver metal figure by Daren Greenhow, standing wistfully in a sea of anemones reaching out holding a bird perched on its hand and set beautifully at the base of a  great tree.
Ringing ceramic bells beneath the maple.
Photo credit: Alida Robey
The delightful family I joined for my tour of the exhibition drew me into things I might otherwise have missed. There was a beautiful maple tree with its new leaves unfurling above us and, as we walked under its canopy, we noticed ceramic bells suspended from its lower branches. All the family had a go at ringing the bells and their tinkling sound perfectly complemented the oriental atmosphere of the tree’s form and foliage. The wonderful thing about garden art is that, in having to endure the elements, it is generally made to be quite robust and therefore also capable of surviving the curious attentions of little children.  It was a great joy to see how much the children engaged with the pieces and delighted in the garden.
Metal sculpture by Daren Greenhow.
Photo credit: Alida Robey
I had gone around the sculpture part of the exhibition, and it was almost as an after-thought that I recalled there was still the Quilting Exhibition to see.  I love quilting, but wasn’t sure I was in the frame of mind to see ‘yet another display of quilting’. How wrong could I have been? I have to say that this ended up being the highlight of my day! I had never seen it’s like. One quilter using seemingly random lines of stitching to create landscapes, another creating a beautiful and very personal quilt narrating her family’s history. The latter used a technique whereby she had printed family photos and mementos of places lived into the cloth of the quilted sections. But the showstopper for me was this magnificent tableau by Jane Bjoroy called ‘True Nature’. Each exquisite creature is made by applying and appliqueing tiny pieces of different coloured cloth finely stitched. The whole scene of individual creatures was lovingly portrayed and beautifully interlinked into a stupendous portrayal of the magnificence and majesty of nature. 

I have scarcely touched the surface of the great talent that was on display throughout the Botanic Garden, and the great love that the people of Bristol clearly have for this haven of tranquillity and creativity. All I can do is use the few glimpses shown here to urge those of you who sadly missed it this year, to make sure you put the date in your diary for 2018!

Nature is an extraordinary sculptor.
Photo credit: Alida Robey
When it comes to it though, I am fundamentally a gardener at heart. It was nature as artist and sculptor extraordinaire that stays with me and which this exhibition highlighted beautifully, both in reflecting nature in art and by drawing attention to the setting.  These ferns (picture) for example, could just as readily have held their own in a sculpture gallery, to my view.
Alida Robey has a small gardening business in Bristol and attended the Botanic Garden’s annual Easter Sculpture Festival for the first time this year. 

Gardening keeps us grounded

Posted on by andy.winfield

By Helen Roberts

Sir David Attenborough once said:

Connect with Nature in any way you can. Contact with the natural world isn’t a luxury – it is actually a necessity for all of us. All we know about the natural world gives us pleasure, delight, expertise, continuous interest throughout the year – joy on many occasions and solace on sad ones. Knowing about the natural world and being in contact with it is the most precious inheritance that human beings can have.

Even containers in small spaces help make a
connection with nature. 

It is the word ‘connect’ that is so fundamentally important in a world that often feels to many people fraught, pressured and tiring. In the ever-stressful environments that humans have to confront, be it at work or home, working in gardens for many is a tonic and a way to reconnect with the landscape. For many it brings peace, a space in which to reflect and feel restored. The physicality of gardening is not only good for the body, it is good for the soul too.

This week is Mental Health Awareness Week; a campaign set up and run by the charity the Mental Health Foundation. People across the nation will get together to discuss mental health through various activities, events, talks and sharing of stories. The theme this year is ‘Surviving or Thriving’ and seeks to look at why so few people are thriving with good mental health. The lovely illustration depicting this year’s theme is rather apt, it shows a tree or shrub growing through the words ‘surviving or thriving’. Gardening undoubtedly can make you thrive on many different levels and it certainly fulfils at least 8 out of the top 10 tips listed on the charity’s website on how to look after your own mental health.
I have seen the benefits that gardening can have on mental health through my work and teaching in horticulture. It can clearly turn people’s lives around, almost like a reset button to recharge and move positively forwards. It helps to build confidence, a sense of worth and forges new friendships and all of this happening as people begin to develop a lifelong love of gardening.
Gardening keeps you active physically, but once you get the gardening ‘bug’ it is mentally energising too. Gardening is both stimulating and relaxing (unless you are digging out a tree stump) and with it comes either peacefulness if working on one’s own or, if working with others, calm chatter. Some people loathe weeding, but I know of a great many who love it either because they can just concentrate entirely on the task at hand (like a form of horticultural meditation) or they get some good thinking done. I think some of my better ideas for writing have come to me when I have been weeding.
With regards to feeding the body, gardening to grow vegetables often means you eat well and nothing tastes better than home-grown produce. I think that people are more likely to eat healthily if they know that what they are about to eat they have put the effort into producing. As a child growing up with access to a family allotment, I was much more willing to ‘try’ a vegetable if it was something that I had grown. So in that sense it makes people more adventurous in their diet and variety is good for healthy eating.
Many of us do not have gardens big enough to grow our own food, and this could be viewed as unfortunate. But as we turn to allotments and community gardens to grow food, we find opportunities to not only reconnect with the landscape, but with people with whom we share at least one shared passion. It is an opportunity to step out of the digital confines of social media and meet with people face-to-face, or at the very least, work peacefully alongside each other in silent companionship.
One of the truly great things about gardening is that it helps to remove boundaries of age, gender and background; if you have an interest in it, then the margins of society that so often leave us feeling alienated and alone are removed. I personally have gardening friends from all walks of life, ranging in age from their twenties into their eighties. Gardening definitely has no barriers and it can be refreshing to meet people who can offer a different perspective or solution on matters (maybe not even related to horticulture). If you have a passion for gardening then you will find others that feel the same. If you garden because you love doing it, then that in itself will make you feel good, both in body and in mind.
In 2013, a review of all the scientific studies of gardening-based mental health interventions found that there was convincing evidence of its benefits. There were reduced symptoms of depression and anxiety and participants described many different emotional, physical, vocational, social and spiritual benefits. In 2015, the JointCommissioning Panel for Mental Health and the Centre for Sustainable Healthcarereleased a guidance document for commissioners of financially, environmentally, and socially sustainable mental health services. The guidance recommends horticulture therapy as an effective, sustainable and resilient intervention to promote mental health.

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.
Important links:

Mycoheterotrophs: the sly swindlers of the plant world

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By Helen Roberts

New plant species are discovered all the time. But it is not typical for plants to be discovered in areas that have been meticulously surveyed. Last year, however, a thoroughly unusual species was found on an island in the Kagoshima prefecture, Japan [1].

Gastrodia kuroshimensis is a mycoheterotroph
discovered last year in Japan.
Photo credit:Kenji Suetsugu/Kobe University


Gastrodia kuroshimensis neither photosynthesises nor flowers. Certainly by no means an ornamental showstopper, it is undoubtedly odd looking with fleshy tubers, the absence of leaves and no flowers. In essence, it resembles a pathetic looking fungal protuberance. Strangely enough, it is not a fungus, but a vascular plant. The fact that it does not photosynthesise means it belongs to a peculiar group of plants that are called mycoheterotrophs, which get all or some of their nutrients from a host fungi attached to a vascular plant. The newly found species, Gastrodia kuroshimensis, is what is termed ‘fully’ mycoheterotrophic in that it depends entirely on its association with the fungus throughout its lifecycle. The relationship between it and the host fungi is not mutualistic – it takes all it needs while offering nothing in return. In other words, it’s a big fat cheat.

Mycoheterotrophs parasitise fungi, which are in turn getting their nutrients from a host plant. The fungi that are preyed upon by these cheaters are usually mychorrizal fungi, with mycoheterotrophs often parasitizing a specific arbuscular mycorrhiza (arbuscular mycorrhiza are those that penetrate the cortical cells of plant roots). In this sense, they are dissimilar to parasitic plants like dodder, which obtain their nutrients by directly taking what they need from the vascular tissue using an adapted root.

Who wants flowers?

The second interesting thing about Gastrodia kuroshimensis is that it is entirely cleistogamous, producing flowers that never blossom. Most plants also produce chasmogamous (cross-pollinating) flowers; it is extremely rare to find plants that are entirely cleistogamous. The term cleistogamy means ‘closed marriage’ and the plant produces flowers that are self-fertilised within closed buds. It is essentially a way of ensuring reproduction [2].

The evolutionary reasons are still a puzzle, but it is considered a way of safeguarding fertilisation if suitable pollinators are not around or they have somehow missed the plant or if environmental conditions are not conducive. It can also aid plants in adapting to local habitats, where both sets of maternal genes are passed onto the progeny, thereby removing harmful gene variants. Being cleistogamous also use fewer resources; flowers that are chasmogamous require more energy to produce. However, in most cases chasmogamous flowers are beneficial as they help to provide variability necessary for adaptation, hybrid vigour and negate the effects of deleterious mutations. The reasons for complete cleistogamy remain unresolved but the discovery of Gastrodia kuroshimensis may well help to answer some of these questions.

Other fungi tricksters

Other plants that fall under the mycoheterotrophic category are orchids, monotropes (a subfamily of Ericaceae), members of the Gentian family, certain liverworts and the gametophyte stages of ferns and clubmosses. Some are quite attractive if you like the look of fungal fleshy looking vascular plants with varying hues of red, white and cream. Some are even striped red and white and so commonly known as candystick. Whatever their appearance though, they are unquestionably interesting. But because or their size and rarity they often go unnoticed, lingering in the background like villainous free-loaders.

Mycoheterotrophs at the University of Bristol Botanic Garden

The inflorescences of toothwort in the pollinator display
this week at the Botanic Garden.
Photo credit: Andy Winfield

A wonderful example of a mycoheterotroph at the Botanic Garden is toothwort (Lathraea squamaria L.). It spends most of its time below ground, but in April it sends up aerial inflorescences about 20-25 cm tall. These were in their full glory in the garden a couple of weeks ago, but can still be seen (see photo) in both the pollinator display on the left as you walk in the main gate, or at the east gate.

Unlike Gastrodia kuroshimensis, toothwort flowers are bisexual and pollinated by bumble-bees.

Stop in over the weekend if you get a chance and have a look at this interesting plant.

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.


Sources:

[1] Kobe University. (2016). Plant discovered that neither photosynthesizes nor blooms.
< https://www.sciencedaily.com/releases/2016/10/161014092115.htm>

[2] Allaby, M. (2016). Plant Love: The scandalous truth about the sex life of plants. Filbert Press, pp. 98-103.

In the guts of bees

Posted on by andy.winfield

By Nicola Temple

We hear a great deal about the beneficial bacteria that live in our digestive system and commonly referred to as the microbiome, which help us turn indigestible materials into nutrients that we can absorb. There are countless probiotic products on the market that are meant to introduce more of these beneficial bacteria into our system, enriching our microbiome. However, humans and indeed mammals are not alone in having helpful microflora in the gut.

The microbes that inhabit the guts of social bees has been of particular interest recently. These microbial communities have been studied for their role in bee health, but also as a model organism to help understand the relationship between hosts and their gut microbes, potentially providing insight into our own system.

The specialised cast of microbes

The microbiome of bees is relatively simple, but very specialised. There are about eight to ten bacterial species, but different species of bee will carry different strains of these bacterial species. The bacteria are so specialised that a strain from one bee genus isn’t able to colonise the gut of a bee from a different genus. This suggests that these bacterial strains have been evolving with their hosts over a very long period of time.

Nest entrance of the stingless bee, Geniotrigona thoracica, is
from Malaysia. Photo credit: Eunice Soh.

Like us, these bacteria help the bees break down complex molecules through fermentation in order to make the nutrients available to the hosts. There’s also evidence that they might help to neutralise toxins in the gut. These friendly microbes also outcompete nastier pathogenic species that can make the host ill. For example, the gut microbes in bumblebees have been linked to lower levels of the parasite Crithidia bombi.

The gut microbes of non-social insects, including solitary bees, aren’t as specialised because they acquire them from their environment rather than from other members of their species. Among social bees, it is behaviours such as passing food between individuals and feeding larvae, that allow an exchange of microbes. However, these exchanges pass along the bad microbes as well as the good.  Beekeepers are painfully aware that pathogens can pass through a colony like wildfire. Social insects therefore need a very responsive system that helps keep these pathogens in check. And the key to this might be a very ancient relationship between the good microbes and the host bees themselves, which allows the bee’s immune system to quickly identify the less desirable critters.

A long-term relationship

Research published this week in the journal Science Advances suggests that five of the species of gut bacteria found in modern social bees have been evolving along with their hosts for about 80 million years. It was around this time that the first solitary bees began socialising with other bees – sharing nests and food resources and making concerted defence efforts. The descendants of these first social bees are the hundreds of species of honey bees, bumblebees and stingless bees that are alive today.
This finding not only shows that social creatures, such as bees and humans, transfer bacteria among each other during the same lifetime, they pass them along generations, enabling the microbiome and host to evolve together.

“The fact that these bacteria have been with the bees for so long says that they are a key part of the biology of social bees,” says Nancy Moran, a professor of integrative biology at the University of Texas who co-led the research with postdoctoral researcher Waldan Kwong. “And it suggests that disrupting the microbiome, through antibiotics or other kinds of stress, could cause health problems.”
The co-evolution of the gut bacteria and the bees is so closely linked, in fact, that the researchers found that when a new species of bee branches off in the evolutionary tree, a new strain of bacteria branches off with it. The result being that each of the hundreds of species of social bees alive today has its own specialised strains of gut microbes.

Human influence on this long-term relationship

It’s currently unknown how toxins introduced by humans, including pesticides, might affect the bee microbiome. There is recent evidence, however, that the prophylactic use of antibiotics by bee keepers in the US has resulted in some gut bacteria in honeybees developing antibiotic resistance.

References

Engel, P. et al. 2016. The bee microbiome: impact on bee health and model for evolution and ecology of host-microbe interactions. mBio 7 (2): e02164-15.

Kwong, W.K., Medina, L.A., Koch, H., Sing, K-W., Soh, E.J.Y., Ascher, J.S., Jaffe, R. & Moran, N.A. 2017. Dynamic microbiome evolution in social bees. Science Advances 3: e1600513.

Kwong, W.K., Engel, P., Koch, H. & Moran, N.A. 2014. Genomics and host specialization of honey bee and bumble bee gut symbionts. PNAS 111 (31): 11509-14.

Look out for the early bumblebee…they’re emerging now!

Posted on by andy.winfield

By Alida Robey

I am always so impressed and uplifted when I see the first bees out, braving the cold and wind to forage in the spring sunshine. The buff-tailed bumblebee (Bombus terrestris) braves the winter, emerging on fine winter days to forage, but another species that you are likely to see right now is the ‘early bumblebee’ or Bombus pratorum.

The early bumblebee (Bombus pratorum).
Photo credit: S. Rae [via Flickr CC by 2.0]

How to tell one stripy buzzing creature from another

Being larger and hairier than honey bees, bumblebees in general have a bit more protection to cope with colder weather conditions, giving them an advantage when it comes to foraging in the early spring. The early bumblebee is common throughout Britain from March until June or July, and in milder parts of the south of England, as early as February.

The Bumblebee Conservation Trust has a very good identification chart and video guide to help distinguish different bumblebee species. When trying to distinguish between species of bee, size, tail colour and stripes are the features to look at. Bombus pratorum is noticeably smaller in size than other bee foragers at work in the spring. Queens, workers and males have a yellow band on the thorax and abdomen, though the band across the abdomen is less obvious or sometimes absent in workers.

The tail is a strikingly dark orange-red, but can be tricky to see as this colouring is only in the final tail section and may also fade with time. Males have a broad yellow collar that wraps around the thorax, and yellow hair on the face.

The bee’s choice of diet

The early bumblebee is a  good pollinator of flowers and fruit, enjoying in particular white clover, thistles, sage, lavender, Asteraceae, cotoneaster, alliums and a range of daisy type flowers; it is also an important pollinator of soft fruit, such as raspberries and blackberries.

Habitat and lifecycle 

B. pratorum’s nesting period is shorter than other bumblebees at just 14 weeks. Queens are fertilised in late summer and then usually go into hibernation. They will emerge from hibernation between March and May depending on the climate in that location and find a place to make their nest. However, because of their short nesting period, they can have two or even three colonies a year in the warmer, southern regions of the UK; new queens mate and, instead of hibernating, immediately start a nest.

At the start of a colony cycle, the queen has a large store of food, which allows her to start laying her eggs to produce workers and foragers who will then gather all the supplies she needs in order to remain in the nest and continue to lay eggs. As the colony cycle nears its end, she will produce more queens before dying herself, allowing the young queens to take up the cycle for the next spring. These young queens will go out to forage for themselves and return to the nest for shelter, but they don’t contribute to the dying colony. When they are ready to mate, the young queens follow the scent of chemical attractants deposited by males. The old colony dies off, with B. pratorum rarely seen after July in the UK,  and so the cycle continues for another season.

The early bumblebee is known for nesting in unusual places such as abandoned bird boxes or rodent nests or just under the ground. Colonies are small at less than 100 workers.

Cuckoos

The bumblebee is no more immune than other creatures to being taken advantage of. Of the 24 bumblebee species in the UK, 6 are ‘cuckoo bees’, which don’t make their own nests, but rather kill off the queen in another nest and get the worker bees to raise her larvae. It is the species Bombus sylvestris, which is a nest parasite of the early bumblebee.

Buzz Pollination

I was intrigued to hear this term, describing a process unique to bees, whereby they catch hold of a flower and by emitting a high pitched buzz shake free the pollen trapped inside (watch a video here). I had also often wondered if bees had any way of knowing whether others had raided the pollen stores before them. It turns out that they have smelly feet that leave a distinctive odour on flowers, which indicates to other bees that the supplies have been raided.

What can we do to help?

As you will know, our pollinators are in decline not just in the UK, but globally.  I was saddened to learn that two species of bumblebee have become extinct in the UK since 1900 – Cullums bumblebee (Bombus cullumanus) and the short-haired bumblebee (Bombus subterraneus). Having lost 97% of wildflower-rich grasslands, we can take action to plant the flowers that are rich in pollen and nectar and therefore of most benefit to bees – some flowers, like pansies, and most double flowers may look pretty, but are of little benefit to bees.

Then there is the whole issue of pesticides. Neonicotinoids, used in some pesticides, are lethally toxic and infiltrate every aspect of the plants systemically – one teaspoon of neonicotinoids is enough to give a lethal dose to one and a quarter billion bees. Professor Dave Goulson, Professor of Biology at the University of Sussex and a bee expert, has been on a mission to see how widespread the use of these pesticides are as plants with a ‘Bee-friendly’ label may have been treated with these pesticides before being put on the shelves of the plant nursery.

Splitting and sharing plants and growing from seed can help ensure the plant hasn’t been exposed to these pesticides – it’s another thing we can do as gardeners to help these valiant and much-assailed vital workers in the garden. Also, as a Friend of the University of Bristol Botanic Garden, you have a unique opportunity to grow special plants from seed collected at the garden!

Another fun way you can help is to take part in The Great British Bee Count using an app developed by Friends of the Earth and which will be running again this year from 19 May – 30 June 2017. This is an initiative to help monitor the numbers of the different bee species found in the UK.  You can see the results of last year’s survey and access various educational resources on their website.

Alida Robey has a small gardening business in Bristol. For several years in New Zealand she worked with others to support projects to establish composting on both domestic and a ‘city-to-farm’ basis.

Sowing Victoria

Posted on by andy.winfield

By Nicola Temple

A photo taken a couple of years ago – I
have a grasp on my son as he leans
over into the tropical pool to get a
good look. Victoria cruziana is in flower
as is the lotus above us.
Photo credit: Shelby Temple

For me, one of the highlights at the University of Bristol Botanic Garden is the giant waterlily (Victoria cruziana) that lives in the pond in the tropical glass house. Its enormous leaves, which can reach 2 metres in diameter, are studded with spines on the underside and always provide ample wow factor for visiting children (my own included).  

The plant is found in slow moving waterways in Brazil, Argentina, Paraguay and Bolivia – in places such as the Pantanal. Its pollination story is an interesting one in that it is pollinated by a beetle (Cyclocephata castaneal). Its white flowers give off a strong scent that attracts the beetles in the evening. The flower then closes around the beetles, trapping them in the flower overnight. The flower produces heat (thermogenesis), raising the temperature as much as 9oC above the ambient temperature outside, which means the beetles can maintain a high level of activity without using as much energy. It’s a thermal reward and the plant benefits as the active beetles will pollinate the flower. The pollinated flower opens the next evening, revealing a new light pink colouration to its petals. The beetles flee the flower and make their way to the next unpollinated flower.

Of course, this species of beetle isn’t found in the Botanic Garden, which makes pollination a bit more challenging. However, there are other insects in the Garden that have filled this niche and the plants have set seed over the last few years. However, this is the first year that staff at the Botanic Garden have tried to sow this seed and, so far, things are going well!
The seeds of Victoria cruziana are kept wet.
Photo credit: Andy Winfield

Replicating the natural environment

In its natural environment, the seeds from Victoria cruziana would be buried in the sediments, stirred up perhaps by grazing capybara and swirling river currents. It wouldn’t be until the high water levels following the rainy season had receded that the water temperature and the amount of light penetrating to the sediments beneath would be sufficient to prompt germination.

In the Botanic Garden, botanical horticulturist, Andy Winfield, first primed the seeds by scratching the tough seed coat with secateurs. The seeds were then sown into topsoil and covered with a layer of horticultural grit. The pots with the sown seeds were then placed in a container of water to a level about 10 cm depth above the seed. This replicates the approximate water depth in the natural environment. The water is heated to a temperature of between 30oC and 32oC; this is critical to start the germination process.

Andy scores the seeds with secateurs
before sowing.
Photo credit: Nicola Rathbone

Victoria cruziana grows around the edges of water bodies and in wetland areas where there is no forest canopy. In order to replicate the amount of daily sun it would be receiving in the tropics and sub-tropics, grow lights on a 12h on/12h off cycle were hung above the pots. Then the whole contraption was covered in plastic film to reduce evaporation and maintain humidity.

Andy had read that germination time is generally about 2-3 weeks in this type of scenario, but within a few days he noticed that the seeds were starting to send out roots and when I visited a week after sowing, the hypocotyledonous stems were clearly emerging from the seeds and shooting upwards toward the surface of the water. 

Preparing to plant Victoria out

At the moment, the water temperature in the pool in the tropical glasshouse is only about 14oC, far too chilly for Victoria. In the coming weeks, however, these plants are

likely to grow quite quickly. Andy and the rest of the team at the Garden will pot them on several

times, gradually reducing their water temperature. At the same time, Bristol temperatures will be increasing and the tropical glasshouse will start getting warmer, as will the pool. By the time the Victoria plants have a few decent leaves, the temperatures between the tropical pool and the plants will have become similar enough that Victoria can be put into the planters in the pond.

The annual light intensity here in Bristol is considerably less than Victoria cruziana would receive in South America. However, the long summer days here mean that during those months more solar radiation is received here in a single day than in tropical South America. This helps Victoria cruziana flourish in the Botanic Garden tropical pool over the summer and it will be worth a visit to see it in flower. See the series of photos below taken the day the seeds were sown.

Andy prepares the loamy mix for sowing.
Photo credit: Nicola Rathbone

The seeds are sown into a loamy mix.
Photo credit: Nicola Rathbone

The soil is covered with a horticultural grit.
Photo credit: Nicola Rathbone

The seeds are sown and are ready for immersion
in a nice warm bath.
Photo credit: Andy Winfield
The pots immersed in the warm bath.
Photo credit: Nicola Temple
Only one week after sowing, the embryonic stem
has emerged and is stretching for the surface.
Photo credit: Nicola Temple

Sources:

Seymour, R.S. and Matthews, P.G.D. 2006. The role of thermogenesis in the pollination biology of the Amazon waterlily 
     Victoria amazonica. Annals of Botany 98(6): 1129-35.