The World’s Shiniest Living Thing
2012 09 12

From: Not Exactly Rocket Science



In the forests of central Africa, there’s a plant that looks like it’s growing its own Christmas decorations. Shiny baubles sprout from between its leaves, shimmering in a vibrant metallic blue. Look closer, and other colours emerge – pinpricks of red, orange, green and violet. It looks as if Seurat, or some other pointillist painter, had turned their hand to sculpture.


But these spheres, of course, are no man-made creations. They’re fruit. They are the shiniest fruits in the world. Actually, they are the shiniest living materials in the world, full-stop.


They belong to a plant called Pollia condensata, a tropical metre-tall herb that sprouts its shiny berry-like fruits in clusters up to 40-strong. These little orbs are iridescent – they use special layers of cells, arranged just so, to reflect colours with extraordinary intensity. This trick relies on the microscopic physical structures of the cells, rather than on any chemical pigments. Indeed, the fruits have no blue pigment at all.


In the animal kingdom, such tricks are commonplace – you can see them at work on the wings of a butterfly, the shells of jewel beetles, or the feathers of pigeons, starlings, birds or paradise and even some dinosaurs. But in the plant world, pigments dominate and structural colours were thought to be non-existent are much rarer.


Silvia Vignolini from the University of Cambridge discovered Pollia’s secret at Kew Gardens in the UK. Her group, led by Ullrich Steiner, was scouring the plant world for species that bend light in interesting ways. Under the recommendation of the Smithsonian’s Robert Faden, Vognolini sought out Pollia, and with help from Kew’s Paula Rudall, she found a sample of the plant. It was collected from Ghana in 1974 but it’s still as vivid as ever. (Unlike pigments, structural colours don’t degrade, so the fruits will retain their sheen for decades to come. Some fossils still keep their iridescence.)


Under the microscope, Vignolini saw that the outer part of the fruit consists of three to four layers of thick-walled cells (labelled “1″ in the image below). Each cell contains yet more layers, made of cellulose fibres. The fibres all run parallel to one another, but each layer is slightly rotated against the one above it, producing an elegant spiral.


As light hits the top layer, some gets reflected and the rest passes through. The same thing happens at the next layer, and the next, and so on. Provided the layers are exactly the right distance apart, the reflected beams of light amplify each other to produce exceptionally strong colours. The technical term is “multilayer interference”. Or alternatively: “Ooh, shiny!”



Many animals use such structures to produce colour. This is why, like Pollia fruits, the wings of many butterflies and the feathers of many birds, can still look stunning after years in a fusty museum drawer. By finding the same structures in Pollia, Vignolini has uncovered a great example of convergent evolution, where species from different branches of the tree of life arrive at the same adaptations independently.



But Pollia fruits reflect more light than any bird or butterfly. Vignolini hasn’t just found the first strong iridescent colours in a plant; she’s found the strongest iridescent colours in nature.

[...]



Read the full article at: discovermagazine.com





Related Articles
Starbucks to stop using red food colouring made from crushed beetles
Radioactive glass used in art to highlight fallout in Japan
We are ALL made of Crystals
The Mandrake Plant and its Legend
Neanderthals Found Certain Plants Important, Had Medicine


Latest News from our Front Page

Pre-historic tokens used in conjunction with cuneiform
2014 07 22
An archaeological dig in southeast Turkey has uncovered a large number of clay tokens that were used as records of trade until the advent of writing, or so it had been believed. But a new find of tokens, dates from a time when writing was commonplace – thousands of years after it was previously assumed this technology had become obsolete. Researchers ...
Are immigration opponents Nazis?
2014 07 22
It seems the usual suspects are calling anyone who opposes unlimited immigration to be a "Nazi". The Left seems to be in constant fear of "Nazis" that lurk in public policy discussions and I assume under their beds. If you oppose any Leftist position, you are a.... take a wild guess...wait for it.... a NAZI! Tim Wise recently went ...
What Did US Spy Satellites See in Ukraine?
2014 07 22
Exclusive: The U.S. media’s Ukraine bias has been obvious, siding with the Kiev regime and bashing ethnic Russian rebels and Russia’s President Putin. But now – with the scramble to blame Putin for the Malaysia Airlines shoot-down – the shoddy journalism has grown truly dangerous, says Robert Parry. In the heat of the U.S. media’s latest war hysteria – rushing to ...
Oh, Great: Robots Are Set to Conduct National Security Clearance Interviews
2014 07 22
Advancing a career in the US government might soon require an interview with a computer-generated head who wants to know about that time you took ketamine. Psychologists at the National Center for Credibility Assessment (NCCA) are developing an interview system that uses a responsive on-screen avatar for the first stage of the national security clearance process. Initial screening for a variety ...
Is Anything on the Internet Real Anymore?
2014 07 22
Is there anybody…out there? I promise I’m a real person asking this question and typing this article…but beyond that, I can’t promise much else about anything you or I see on the Internet. This article on ZDNet, “GCHQ’s dark arts: Leaked documents reveal online manipulation, Facebook, YouTube snooping,” confirms — beyond a shadow of any possible doubt — that a barrage of ...
More News »