For the past few months I’ve been working on a really exciting exhibition opening on the 20th of May: Object Lessons #MMObjectLessons Object Lessons celebrates the scientific model and illustration collection of George Loudon. Each of these finely crafted objects was created for the purpose of understanding the natural world through education, demonstration and display. […]
Guest blog by: Sophie Mogg (with images and introduction provided by Rachel Webster)
It’s always a joy to see something growing through these dark and dreary winter months. With glossy, green leaves, little cream bell-like flowers and big, red berries that start to appear as the snow melts, today’s plant, Gaultheria procumbens, is a very popular choice for baskets and containers. The name of this plant originates from Pehr Kalm, a Swedish explorer who named this plant after his good friend, Dr. Hugues Gaultier who expressed huge enthusiasm for the plant’s potential for tea.
Gaultheria procumbens goes by many common names such as the Checkerberry, Mountain Tea or my particular favourite la Petit te du bois meaning “the little tea of the woods”. The “tea” part of these common names refers to the fact that the leaves can indeed be brewed for tea however unlike that of Camellia sinensis, the leaves must be left to ferment in order to produce a distinct flavour. Drinkers of this mountain tea suggest that you place several leaves in a jar that can be sealed with boiling water and then cover said jar with a cloth or tea towel. The leaves must then be left to ferment for roughly 3 days in a warm environment, or at least till you can see small bubbles appearing. The liquid can be drained from the jar and stored, being diluted and warmed when required. The left over leaves are then dried and can be used again to make a more delicate flavoured tea. The leaves are evergreen and so can be harvested all year round to produce tea however it is suggested that you only take one or two leaves from each stem.
The essential oils of the leaves, known as oil of wintergreen, contains methyl salicylate and relative of aspirin and is known to act as a natural painkiller however those who are allergic to aspirin should avoid Gaultheria procumbens.
The small berries produced by Gaultheria procumbens is often referred to as “teaberries” and these are also edible with a mild minty wintergreen taste. The unripe berries are a pale green-white colour but soon ripen to a beautiful rosy red with a star-shaped depression on the bottom. They can be eaten raw or cooked to produce pies, jams or jellies.
Guest blog by: Laura Cooper
Whilst volunteering at the herbarium I came across several small boxes containing bewitchingly bright red seeds and an equally garish TOXIC sign. They were labelled Abrus precatorius seeds, and that one of their common names is the rosary pea suggests that I am not the first to be taken in by their beauty. The seeds of Abrus precatorius have the eye-catching red of hawthorn berries capped with a black spot at the hilum, but glossy and sturdy enough to be drilled to make beads for jewellery.
The contrast between the beauty of the seeds and their toxicity inspired us to begin a blog series on toxic plants called The Poison Chronicles. We want to look at how they can kill, but also why they have evolved this ability and if the plant has any other products that are medicinally useful.
Abrus precatorius is a vine in the Legume family native to the Old World Tropics, but was introduced to the Neotropics for it’s ornamental value, but is now an invasive species. It proliferates after a forest fire so can out-compete slower growing plants, it’s suckering ability makes it difficult to remove.
But these seeds are more than just beautiful. They have earned their TOXIC label as they contain the toxin abrin, which has a very low fatal dose, reported in the literature as around 0.1 – 1μg/kg, making it one of the most toxic known plant products. Abrin acts by inhibiting protein synthesis, so can affect all cells in the body. A few hours after a person has ingested a lethal dose of abrin, they may experience severe vomiting, gastrointestinal bleeding, dehydration, multi-organ damage and death often within 36-72 hours. The incredible toxicity of abrin was occasionally used to secretly kill people in 19th century Bengal. The seeds were ground into a paste, shaping into a point known as a sui and left to harden in the sun. This was then mounted on a handle and stuck through the person’s skin by a surreptitious slap to the cheek.
Despite this toxic plant being widespread, there have been very few cases of abrin poisoning. The thick indigestible coat of mature seeds meaning that if seeds are swallowed whole, they are unlikely to release much abrin and symptoms are mild. Chewing the seed releases the toxin, and it has been reported that a single well chewed seed could kill. However, a case of a patient attempting suicide through ingesting 10 crushed A. precatorius seeds survived after swallowing activated charcoal. Except when used or taken deliberately, it is surprisingly difficult for humans to be poisoned by A. precatorius, so for most this plant poses more of a threat to your garden as an invasive than your health.
An obvious question is why these seeds contain such a deadly toxin. I have been unable to find any research on this. But it may be that the thick seed coat means the toxin isn’t a defence against herbivores ingesting the seeds at all. As it has been reported that the seed is dispersed by birds who would not chew the seed and would instead disperse them in faeces, it is possible it is a defence against mammals chewing the seeds.
A. precatorius has not always been seen as a deadly beauty, and has been used a traditional medicine. Extracts of the seeds have been used in the Pothohar region of Pakistan as a purgative and an aphrodisiac and in rural Bangladesh to treat erectile dysfunction. The symptoms of poisoning by abrin suggests very low doses could work as a purgative, there is a high risk of administering a lethally high dose.
A. precatorius‘ entire biochemical system makes it toxic, so single chemical plucked out of this network can have very different properties from the plant as a whole. In contrast its traditional uses, experiments have been done which show that abrin injected into laboratory mice damages the DNA and reduces production of sperm cells, though the long time period needed for DNA repair to occur means it is unlikely to be used in commercial birth control.
Abrus precatorius demonstrates the multi-faceted nature of plants: at once a beauty and a (potential) killer; a toxin and used as a medicine.
We hope you have enjoyed our first installment of The Poison Chronicles. You can find more information following the link below
What wondrously poisonous plant would like to find out about next? Leave your comments below.
Guest blog series by: Sophie Mogg
Cotton, we’ve all seen it, heard of it and probably worn clothes made from it too. In today’s installment we’ll be taking a look at Gossypium arboreum, the species of cotton native to India and Pakistan. This particular species was supplied as a single specimen by Carl Linnaeus for his herbarium and was recorded within his own book, Species Plantarum 1753.
Cotton has been cultivated in South Asia from around 3300 BCE. It is a perennial shrub, reaching approximately 2M tall and grown more like an annual due to being harvested every year. The leaves of the cotton plant are lobed, typically having 3-5 lobes and bearing a close resemblance to maple leaves. The seeds are contained within the boll, a small capsule and individual seeds are surrounded by two types of fibres known as staples and linsters. The former is produced into high quality textiles where as the latter produces lower quality textiles. Whilst Gossypium arboreum and its sister plant, Gossypium herbaceum (Africa) only form 2% of the world production of cotton, new varieties of these species are being bread for more desirable traits. One such variety is Gossypium arboreum var. neglecta grown along the Meghna river. This variety, known as “Phuti karpas” is used to make Muslin in Bangladesh as the cotton fibres can be spun to produce threads are more resistant to breaking at higher counts.
The fibres can be separated from the seeds either manually or by use of a machine known as the cotton gin. There are two types of cotton gins, the saw gin for the shorter fibres and roller gin for the longer fibres. The roller gin was invented in India and is used to prevent damage to the longer fibres. Once fibres are separated from the seed they are compressed into lint bales and graded. Carding is the next step, where fibres are pulled so that align parallel to one another and eventually form a sliver which is a rope-like strand of cotton. The slivers are combed to remove impurities before being drawn out into thin strands (roving). The final processing step of cotton is the spinning, where the roving is drawn out and twisted for form yarns and threads for weaving to produce textiles.
Towards the end of the 18th century Manchester had begun to build steam powered mills in order to work with cotton and by 1871 was using approximately 30% of the cotton produced globally. Over 100 cotton mills were built during this time and the industry was supported by The Exchange where over 10,000 cotton merchants would meet in order to sell their wares. The start of the cotton industry across Britain coincided with the Calico act of 1721 being repealed allowing British companies to use cotton in order to make calico, a cheaper and less refined cotton textile, into clothing. Cotton textiles soon became one of the main exports of Britain and is still one of the worlds most used fibres today.
If you are interested in finding out more about plants from Asia over the next few weeks please fill out the poll below.
If you would like to learn more about cotton and the cotton industry follow the links below:
I’ll soon be travelling to other parts of Asia so I hope you continue to join me. Look for future blogs exploring dyes, medicines and potentially poisons. As always, don’t forget to leave a comment about what you’d like to see from our collection.
The Museum staff – all a bit giddy in the garden after an intensive afternoon discussing our courtyard project.
And so we begin….to kick off four years of redevelopment, we had an all staff half day on Monday 6th June. It was a jam-packed afternoon of activities, led by our Director Nick Merriman, setting the scene for the Courtyard Project and getting everyone up to speed on where we are now and what we are planning for the future.
Susie from Modern Designers then took over for a great session on branding, which helped us to think about what makes a successful brand and how we currently communicate about the Museum.
Henry (our Head of Collections) and I then led an activity – based on some excellent work done by Common Cause Foundation – that explored what our personal values are and also the values we think our visitors associate with the Museum. It was a really insightful piece of work that helped us to capture the variety of…
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We already have the Herbology blog and the herbarium on twitter (@aristolochia), but from 2016 we will also be contributing images to the Manchester Museum’s Instagram account. So if you’re on Instagram and are interested in museums, herbaria or just beautiful things – please take a look at our images.
We have a large collection of lantern slides from the Manchester Geographical Society in the museum stores, including some of Iceland, and they gave us a window onto the lansdscapes of the past. Some of the most striking were images of Thingvellir National Park.