Believe it or not - plants can 'smell'. That is, they can respond to volatile chemicals in the air. A plant senses a smell when the chemicals blow over the leaves. The plant inhales the chemicals through the stomata on the leaves.
One common thing that plants use 'smell' for is to know when to ripen fruit or as a device to drop their leaves in the autumn. The chemical that generates this response is called ethylene. An old example of this in action is when people put a hard fruit, such as an avocado, in a paper bag with a ripe banana. The ethylene produced by the ripe banana acts to soften up the avocado.
Research, primarily by Dr. Consuelo De Moraes, has shown that plants such as the parasitic dodder vine use smell to find a plant to parasitise. In trial she found that the dodder would grow towards the tomato plant. In fact, when the chemicals that make the smell of the tomato plant were isolated and put on a piece of cotton, the dodder would even grow towards that. The chemical that the dodder likes so much is beta-myrcene. More information can be read in "What a plant knows" - information in the references below.
Plants also use smell for defence. This was originally discovered by David Rhoades and Gordon Orians, but many experiments have been done since. The experiements show that the chemicals are given off when a leaf is being damaged by a herbivore or a bacteria to let other leaves on the plant know that it needs to increase chemicals to repel the herbivore or to attack the disease. If another plant is close enough it will also 'smell' the chemicals and increase its' defence.
Plants also use smells to attract animals. Some plants like the bluebell has smells that we find utterly desirable and when possible we will spread them throughout the world - primarily by planting them in our gardens. Others, such as the titan arum produce the smell of rotting flesh - it even heats itself to 30 degrees centigrade to ensure that this smell travels far and wide. Why does it do this? It does it to encourage its' pollinator - tiny sweat bees.
References
Chamovitz, D. (2012) What a Plant Knows, Oxford, Oneworld Book.
Etymology This word comes from older variants of languages in use today, such as Old High German and Middle Dutch. In Old English the original word was a compound word made from the verb 'Gird' and the suffix 'le'. Gird meant to surround the waist.
Meaning
The usage that we're looking at today relates to the girdling of a plant. In this way the stem is cut right around its circumference cutting through the phloem. This means that the downward transport of substances, such as those created by photosynthesis, cannot happen. This can easily kill the plant.
Usage and examples
Diseases such as Phytophthora ramorum, discussed in the Wild Things television programme, uses girdling as part of its attack of susceptible trees. This can lead to the tree 'bleeding' and is discussed in this Forestry Commission video:
However, it is not just diseases that does this to plants. Animals, such as deer and birds, can girdle a plant during their normal grazing and even humans can use this technique to encourage larger fruits.
An example of accidental girdling can happen when saplings are planted with support around their trunk. While there is lots of room to begin with, people may not return to remove the support and within a few years the friction caused by the support can act to girdle the tree. Below is an example of girdling:
History
1662 is the earliest example of girdling relating to plants that the OED has records for. The comment was written by a J. Winthrop regarding trials of girdling trees. It seems that this may be a fairly recent usage of the word as J Winthrop says: "by girdling the tree (as they call it"
Bibliography
"girdle, v.". OED Online. March 2013. Oxford University Press. 28 March 2013 <http://www.oed.com/view/Entry/78469>.
"Girdling". Wikipedia Online. March 2013. Wikipedia.org. 28 March 2013 <http://en.wikipedia.org/wiki/Girdling>.
Allaby, M. (2012) Oxford Dictionary of Plant Sciences, Oxford, Oxford University Press
Like us, plants can 'see' meaning that they can detect electromagnetic waves and respond to them. This is very important as light equals energy to a plant - so the response to light stimulus can be when to grow or how fast to grow.
Charles Darwin, and his son Francis, performed many experiments on plants during their careers. One particular experiment found that light hitting the tips of plant stems make the plant respond by bending towards the light: Phototropism.
Plants also respond to the changing day lengths through the year. Known as Photoperiodism, the plant can detect the continuous length of darkness each night and reacts. This reaction to darkness is used on many plants, for instance the humble chrysanthemum. By switching on a red light just for a few seconds each night throughout the autumn and winter (the usual time for flowering), the chrysanthemum is prevented from flowering. Then two weeks before Mother's Day the darkness is not interrupted by switching on the light - this length on continuous darkness makes the plant respond by flowering - just in time to be shipped to supermarkets!
Plants are also regulated by the Circadian clock, just as we are. This developed well before there was a split that developed into the Plant Kingdom and the Animal Kingdom. It would seem that these clocks may have developed to prevent damage from high UV radiation. Seen in humans as sun burn.
Blue light is used by the plant for phototropism and the Circadian clock. Red light is used by the plant to know when to flower. Far red light, the red seen for a short period as the sun goes down is used by the plant to shut down for the night. And genetics is finding more and more photoreceptors showing the complexities of plants.
References
Chamovitz, D. (2012) What a Plant Knows, Oxford, Oneworld Book.
Etymology Fen seems to be a very old word appearing in languages such as Old Norse, Old English, Old Frisian, and Old High German, among others. Meaning
A fen, in the usages we're looking at today, is an area of wetland vegetation. They stay so wet due to water being received by rainfall and ground water flow.
Usage and examples A fen is an ecosystem that creates peat. This is the fabled growth media for gardeners, the use of which is gradually being faded out by law. Leading many companies to investigate alternatives.
The fens are also well known areas for archaeologists as the anaerobic conditions found in the waterlogged soil prevent wood from decay.Flag Fen, first discovered by Francis Pryor, is one such site.
The fens are often confused with bogs. While bogs and fens both have peat in them, the fens have a greater water exchangeand are less acidic, therefore their soils are higher in nutrients. Due to the acidic and low nutrient soils, bogs are home to some carnivorous plants, such as the Common Butterwort (Pinguicula vulgaris), seen below. If you look closely, you can also see a sundew just below the leaf pointing directly left.
History
The earliest use of the word fen that the OED has on record is c888. It was used by Ælfred, King of the West Saxons and of the Anglo Saxons. He was important for speakers of English because he ordered the translation of many texts into the English spoken at the time. This was a dialect of Old English known as West Saxon English.
Bibliography "fen, n.1". OED Online. March 2013. Oxford University Press. 19 March
2013
<http://www.oed.com/view/Entry/69207?rskey=loQjgC&result=1>. "Flag Fen" Wikipedia.org. March 2013. 19 March 2013 <http://en.wikipedia.org/wiki/Flag_Fen> Allaby, M. (2012) Oxford Dictionary of Plant Sciences, Oxford, Oxford University Press Seargeant, P and Swann, J (Eds) Worlds of English, Abingdon, Routledge "Bogs, Fens and Pocosins " nhptv.org. 16 April 2013 <http://www.nhptv.org/natureworks/nwep7f.htm?
Date Photographed: 14/02/2013
Location: River Avon, Melksham
Resources: http://www.arkive.org/mute-swan/cygnus-olor/
Notes: Our only resident swan, also Britain's largest bird. Can be identified by its orange beak.
I was reading the Real Life Minimalist post on Miss Minimalist today and came across the word 'lagom' in Jess' post. As often occurs when I read a new and interesting word, I went off to explore what the digital landscape had to offer about this word and its meaning.
Lagom (pronunciation) is a Swedish word and as such there was no entry in the OED, but simply putting the word into Google brought me to the Lexiophiles.com site and the entry "What “lagom” Really Means ".
Lagom seems to be a neutral word that inspires people to live life with 'just enough' and a feeling of what is 'just right'. I like the word because it feels like it is packed with integrity and allows people to go with the flow of not too little, but not too much.
The Lexiophiles page also speak of Aristotle's 'Golden Mean'. Research on this brings us to an example in Aristotle's book on Politics where Aristotle criticises Spartan policy because they train only their men and not their woman and this training is only for war and not peace. Joined with Gautama Buddha's teaching on the middle way, we can see that extremes have been worrying our best thinkers and teachers for thousands of years.
But how do we embrace lagom; the golden mean; the middle path? I think as with all things there will be a period of growth whereby we go to extremes in our attempts to reach this middle ground. An example when trying to reach your minimalism point can be seen when we first find out about the wonders of decluttering and minimalism and 'sell, sell, sell' in order to reach the nirvana that we've read so much about - but then as if on auto pilot we overcompensate and things start to accumulate again.
But this too, is fine. It is part of the process. It is only by living with too much and too little that we can understand when we have achieved lagom. And by achieving lagom we can then begin to understand that it is true to its definition and that 'just enough' will change throughout our lives - which too, is just right.
First published in 2006 and first read by myself in 2007, Homo britannicus was the first book I ever read about ancient humans and sparked an interested that has stayed with me ever since.
I have just re-read this book because it contains so much information that I decided to create a timeline in Excel. This timeline will help me understand in a wider context what happened when.
Chris Stringer begins with a chapter about how research into geology and anthropology began and how it then developed into the knowledge and methodologies that we have today. He isn't shy about some of the historic mistakes made by individuals in his field either and looks in some detail about whom may have instigated the Piltdown Man forgeries.
Going through the ages in each chapter, starting with around 700,000 years ago. Mr Stringer weaves together the theories and evidence in this multidisciplinary investigation to the ancient humans that have lived on our little piece of the planet. The AHOB (Ancient Human Occupation of Britain) team gather together evidence that can tell us in great detail what species of human were around and the tools they were using, what plants and animals were around, and therefore what climate was experienced at different periods of Britain's history. It is this approach that draws you into the book and keep you there. Experiencing the excitement of the finding, as if it were you systematically revealing the fossils of the 'red lady' of Paviland and not William Buckland.
The book closes by drawing together evidence of climate in our past and looking at the factors that affect our current climate before extrapolating what the worse case may be if things carry on in the projected manner.
I initially read the paperback version of this book before asking for
the hardback version - the hardback, to me, is a much better experience
because the images and photographs flow and progress with the text
rather than being confined to a couple of plate sections.
This book is a must for anyone who is interested in learning about our country through the past 700,000 years and the humans who resided here. In truth, I feel, it is a book that should be in comprehensive schools throughout the British Isles.
Own or Loan: Own
Read Again: Yes
Recommend: Yes
Overall out of Five: 5
To celebrate the recent achievement of 2 million active Geogaches on Geocaching.com, here are 5 fab facts about Geocaching:
Coined backed in 2000, Geocaching is the term that describes those of us that hunt treasure (caches) using a GPS Device.
Dave Ulmer was the first person to hide a geocache. He hid it to test the accuracy of the improved GPS signal available to civilians.
Geocaching.com is one of the main providers of geocaching adventures. They currently have 1,999,615 active (that's available to find) geocaches in over 180 countries.
There are many types of cache available, and therefore adventure to be had, including traditional caches, multi-caches, and my favorite: Earth caches - for which you can be awarded.
You can even use travel bugs to increase the fun! Travel bugs are game pieces that travel from cache to cache with their own little mission. Sometimes that mission is to reach a certain place, sometimes it's to reach certain caches - eg. caches at motorway service stations. You can even view their progress on Google Earth and see the, sometimes, many thousands of miles they have travelled since first being placed.
If you want to give it a go just create a free account at either of the sites below. You will also need either a dedicated GPS device, or if you have a smart phone then you'll need to download an app for that!
Term and pronunciation Epipetalous (epee-peta-luss) Etymology This word is a combination of the prefix - Epi combind with Petal and closed with the suffix Ous. Meaning
The stalk of the stamen, the filament, grows upon the sides of the corolla.
Usage and examples
The corolla being the collective term for petals of the flower. Therefore this means that only the filament part of the stamen is fused to the petals; the anther is not connected to the petals.
Plants that show this type of growth include primulas and petunias
Here's an example from: http://herbarium.usu.edu/images/Dicots/Primulaceae/primula2.jpg
History
The earliest reference to the word epipetalous occurring in the OED Online is by John Lindley in the publication School Botany in 1839.
Bibliography "epipetalous, adj.". OED Online. December 2012. Oxford University Press.
12 March 2013
<http://www.oed.com/view/Entry/63444?redirectedFrom=epipetalous&>. "Stamen" Wikpedia.org. February 2013. Wikipedia 12 March 2013 <http://en.wikipedia.org/wiki/Stamen> "Primula2" Herbarium 14 March 2013 <http://herbarium.usu.edu/images/Dicots/Primulaceae/primula2.jpg>
This week I've grouped together five of the main types of seed dispersal other than dispersal by humans. Each one is illustrated by video clips on YouTube.
Dispersal by wind
This is a rather primative form of seed dispersal and is very wasteful. But as long as one or two seeds eventually germinate, then the parent plant has done its' job.
Dispersal by water
Some plants have evolved to ensure that their seed is protected even if it falls into water and is carried for an extended period of time. In the video is the example of the mangrove seed, which may fall directly into the mud below it - but is often carried many miles before it can continue growing.
Dispersal by animals
Animals mainly disperse seed after eating the fruit that surrounds the seed. In this case it is in their droppings, an example being seeds dispersed by birds. The example in the video, though, is of ants. Who take the fruit underground and feed the elaiosome surrounding the seed to their larvae. The seed is then 'dumped' into an underground chamber, where it can then germinate.
Dispersal by attachment to a carrier
A method of seed dispersal for many of us. Finding the burdock seed stuck to our trousers or the dog, then picking it off and letting it drop to the ground. Quite a sneaky method of getting your seed to new ground.
Dispersal by explosive release
This is probably the coolest method of seed dispersal! Often seen in tropical regions where there is little wind to carry the seeds to new ground.
Bibliography
RHS The Garden, February 2013. Lancaster, N
This is the companion book for the 2012 series; Kingdom of plants. The series was presented by David Attenborough and took place over a year at the Royal Botanic Gardens, Kew. It was shot in 3D, which was no surprise as Sir David is always keen to remain at the forefront of new broadcasting technology, and was shown on Sky. It was a fantastic series, one that I really enjoyed. (ETA: A review of the series can be found over on the AOB blog).
But it wasn't until recently that I realised that there was a book to accompany the series.
Quite often when a book is written as a companion to a television series, it can be a run of the mill publication that repeats word for word the commentary from the episodes. Luckily, for me, this is not one of those books.
This is one of those books that is allowed the room to breathe and really let us in to the world of plants. The tag line is "A Journey Through Their Evolution" and it is a journey that we get. The first chapter is especially good at providing dates for when evidence has suggested milestones in the evolution of plants and as such has provided a wealth of new data for the timeline I am creating in Excel as a tool to help me understand the timescales of when such things occurred. The only potentially negative thing I have to say is that after the first chapter, dates are few and far between. However, this may be because there is no evidence to suggest dates as yet, rather than the author leaving known dates out - as I'm still new to plant science, I don't know.
The television programme ran over three episodes, which was around 2 and a half hours. with such a limitation of time, only the briefest of brief overviews can be given - and spectacularly given it was. The book has wonderful photography and Will Benson, the author, writes in such a way that pages slip past without thought. He writes in a way that the information can be retained and understood without it feeling cumbersome or overwhelming.
The book has nine chapters which conclude with a chapter entitled 'No Plants, No Humans'. A sensible way to end such a book as I think a lot of us do forget that while flowers can be lovely to look at, the plants serve a much higher purpose. Throughout its 256 pages, this book explains that purpose wonderfully.
Own or Loan: Own
Read Again: Yes
Recommend: Yes
Overall out of Five: 4
Well it’s here. The last episode of Wild Things. It’s been a fantastic journey, especially for people like me who are interested in plants, fungi, and lichens; but that don’t yet know much about them. Not only have we learned about the plants that are thriving and those barely surviving, but we’ve learned some basics about how plants work.
Anyway, on to the episode…
Joining the team on the Merseyside, they split up to investigate the wild things. Chris starts with the art installation ‘Another Place’ by Anthony Gormley of 100 life size statues looking out onto the busy shipping lanes of Liverpool docks. Finding that these statues have been covered by the Australian barnacle.
These barnacles arrived in the 1940s, hitching a ride on the ships. Slowing a ship by up to 10%, these barnacles can be a real pain and Sally shows us that they can even grip the most smooth surface made by science – the non-stick coating on frying pans! Before growing a shell, the baby barnacle, or cyprid needs to find a place to stick to so it can move on to the next stage of its life. Using a light microscope we see the cyprids slide around the pan. Using its antennae it find purchase it tightens its hold – permanently – exuding a sort of biological cement. These long fibres bind together very tightly allowing the barnacle to make the connection it needs.
Next Chris finds a special moss; the tall clustered thread moss. Special not only because it was only found on the zinc spoils of old lead moss, or because when these mines closed it was on the brink of extinction due to habitat loss, but because it have found a new habitat. This new habitat is under metal fencing, under what Chris called the metallic drip zone. The rain runs down the fence taking with it small deposits of metal from the fence with it. This moss really needs such high metal content to thrive. Chris runs an experiment on the alpine penny cress to give us an idea of what it does with this metal. Using a x-ray image, we see that at cell level the plant stores the zinc just under the skin, but still in the upper layer of cells. This makes it difficult for animals to eat the plant and for the tall clustered thread moss, this has helped it extend its range.
In part two we investigate a pond plant that does need light to grow. This plant is the New Zealand pygmyweed and it’s clogging up our ponds and waterways . From next to no plants on the map 50 years ago, it is now prevalent throughout the UK and is on a government black list. A quick Internet search brings up loads of information on management and eradication of this species – it has even been known to close canals. Plants use light to photosynthesise and store carbon dioxide with the process stopping during hours of no light. The pygmyweed stores carbon dioxide throughout the day and night. It stores the carbon dioxide as malic acid, when the sun comes up it then uses this during photosynthesis. In its native habitat it cannot photosynthesise during the day because its leaves would be scorched. Therefore it has evolved to grow in the cool of the night, but over here in Britain is can grow for around 20 hours each day. This enables it to out complete all of the native plants to Britain, growing up to 6 inches ever 24 hours. Even when Trevor liquidises the pygmyweed, he explains that even a branch of this plant 5mm long will grow into a new plant! The abilities of plants is wondrous – but sometimes no good for a healthy ecosystem in Britain. Therefore small pieces carried by birds can populate new ponds and waterways. Perhaps an insect from its native homeland can help us control this plant by acting as a biocontrol.
Built 400 years ago, Speke Hall http://www.nationaltrust.org.uk/speke-hall/ is our last stop. It was built when Liverpool was a farming settlement made of around 500 people. What are we doing here – we’re supposed to be investigating industrial Liverpool, I hear you ask! Well hold your horses as Sally has the explanation. The timbers that were used to build Speke Hall had lichens growing on them before they were cut down. The then died leaving little dots – the dead bodies of lichens. Using the light microscope we can look at the 500 year old spores of lichens that used to flourish in this area. The spores of this lichen that they find has never been recorded in Liverpool – showing that industry has polluted the air and destroyed the habitat for this lichen. But not forever, this lichen – the Arthonia Radiata, is making a comeback as our air gets cleaner due to the decline in heavy industry.
Well peeps, that’s the end of the series. But it doesn’t have to be an end to our learning on the endlessly fascinating topic of plants and their habitats. One place to start is to follow the team on twitter:
Bioluminescence is the production and the emission of light by a biological organism and means 'living light'.
The bioluminescence is created by a chemical reaction either in the cell of an organism or that of a symbiotic partner living within the organism.
While bioluminescence can be found in many organisms around the planet. Around 90% of marine life in our deep oceans are thought to produce bioluminescence.
Before the invention of safe lighting down in the mines, dried fish skins were used as they produced a faint phosphorescence. However, there was undoubtedly little light in the mines during those days!
Bioluminscence seems to be used for many reasons, including reasons in this non-exhaustive list: communication, locating food, attracting prey, camouflage, mimicry, and self-defense.
