Magnificent May

How did it get to be May already? It seems a very short time ago that we were looking at the low sun and listening to the lone robins sing, bare earth and branches waiting for a temperature hike. Well, the Garden has plumped up with leaves and life, almost fluorescent in its vibrancy. It’s a wonderful time of year, even when it rains you can almost see the plants growing. 

While the rain is soaking into the May soil, it also threatens the flowers of one group of plants in our Chinese Herb Garden. This year we have completed our peony garden, a unique display here in the west country, and on Sunday 12th May we’re holding a day dedicated to peonies in celebration. One thing we’d like for people to see in this area is of course the flowers of peonies, and the weather was doing its best to rain on our peony parade. So we decided to pamper these plants with an umbrella each. It might seem over the top, but it’s a treatment that some of them are accustomed to. In days gone by the gansu mudan peony has led a life of privilege; ancient China knew it as the Emperor’s flower and law decreed that it was only grown in his gardens. Specialist growers were tasked with cultivating it for use in the imperial borders, but if anyone got ideas above their station and sneaked some in their own garden, well, they were executed! So some of these peony flowers have the air of ‘an umbrella is no more than I deserve’.

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Tea, thatch and early spring

Crocus appearing in the Garden.

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. (more…)

The new Australian display

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

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.