Category: Fun Facts

Fun Fact: Acacia trees and rewards

June 16, 2022

Fun Fact: Acacia trees will change the rewards they provide to their symbiotic ants depending on how good they are at their jobs.

Swollen-thorn acacias, most famously Vachellia collensii, are known for their symbiotic relationship with ants. They provide a bunch of services for their trees, including attacking herbivorous insects, clearing encroaching vegetation, and even protecting them from disease by distributing antibiotics synthesized by bacteria living on their legs. In return, the trees reward their ants with food in the form of protein-rich Beltian bodies and sugar-rich nectaries, and with secure housing inside hollow thorns that have evolved specifically for the purpose. Sweet deal.

One of the best-known ant symbionts is Pseudomyrmex spinicola. They do everything expected of them and help their host plant to thrive. The kind of neighbour you’d lend a cup of sugar to (literally). Crematogaster crinosa however, is a little less desirable. They are lazy defenders against herbivores, fail to clear encroaching veg, and are not known to spread antibiotics. A bunch of formic freeloaders. Considering the difference in services, you’d think the acacia would pay their little buddies differently. And you’d be right… although probably not in the way you would think.

In a three-month study, Amador-Vargas and Gijsman (2021) monitored acacia trees at two sites, one which supported both ant species, and one with only P. spinicola. The authors found that the quality and quantity of accommodation (thorns) remained the same between the two sites, but the food rewards did not. Acacias with colonies of only P. spinicola produced nectaries along the bases of their leaves, while those also supporting C. crinosa sported them at their leaf tips too. Rude. The authors suggested that the extra nectaries encouraged the lay-about-Larry’s to traverse the leaves to reach an extra reward, leading them to drive away pests they might not have encountered otherwise. Hardly seems fair to the poor P. spinicola who did not need to be bribed to achieve the same goal.

If you’re interested in further reading, see their paper: Gijsman, F., González, Y., Guevara, M. et al. Short-term plasticity and variation in acacia ant-rewards under different conditions of ant occupancy and herbivory. Sci Nat 108, 31 (2021).

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Fun Fact: Banyan Trees

June 8, 2022

Fun Fact: Banyan trees (Ficus benghalensis) can walk…

So you’d better tie up your ficus before it runs off to join an Entmoot. (I hope I’m not the only one chuckling at that joke, it’s a pretty good one).

Banyan trees, or strangler figs, start off life as epiphytes when their seeds land on the branches of another tree. Once the seed germinates, it sends aerial roots down around the trunk of its host tree, which eventually dies and rots away, leaving the hollow trunk of the banyan. As they grow, banyan trees continue to send aerial ‘prop roots’ down from their branches to support their massive structure. Eventually, the original trunk will die and one of the prop roots will become the new main trunk. This cycle can continue on for centuries with old trunks dying away and new prop roots carrying on, which is a sort of walking… I suppose.

One of the biggest known banyan trees is the Great Banyan near Kolkata, India. It covers more than 4.6 acres and can shelter over 20,000 people.

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Fun Fact: Plant memory

June 2, 2022

Fun Fact: Your house plants remember when you left for holiday without watering them, and they are not happy about it.

Researchers at the University of Western Australia have shown that the sensitive plant (Mimosa pudica) can not only learn from experience but can also remember those lessons weeks later. M. pudica, is a perennial plant in the pea family (Fabaceae) and is native to the Caribbean and South and Central America. It is known for its rapid movement where it folds up its leaves as a defence mechanism when touched or otherwise suddenly stressed (nyctinastic movement). You can often find sad little M. pudica plants at nurseries that have been harassed by passers-by. Please rescue them.

The researchers from Australia found that the M. pudica they were studying for an unrelated research question quickly stopped curling their leaves in response to being ‘alarmed’ but not harmed. The authors suggest that this shows that they had learned that folding your leaves in this scenario was a waste of valuable energy. Furthermore, they found that their subjects remembered this lesson and didn’t close their leaves when exposed to the same “scary” situation a month later.

If you are interested in further reading on the M. pudica study, see their paper: Gagliano M et al. 2014. Experience teaches plants to learn faster and forget slower in environments where it matters. Oecologia, published online January 05, 2014; doi: 10.1007/s00442-013-2873-7

For a (satirical) discussion on its implications, follow this link:

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Fun Fact: Sailor’s Eyeballs

May 26, 2022

Fun Fact: The largest single-celled organism is an alga called Sailor’s Eyeballs.

Valonia ventricosa is found in tropical and subtropical ocean regions around the globe, and is one of the largest, if not the largest, single celled organisms. It is coenocytic, with several cytoplasmic domains, each with its on nucleus and set of chloroplasts, connected by cytoplasmic “bridges” of microtubules. Thanks to this structure, the single cell can grow up to 9 cm in diameter. Pretty impressive considering you need about 5 million cells to make a fly.

Because V. ventricose is such a large cell, it has been used by scientists to study the transfer of water and other fluids across biological membranes. These studies help us understand more about cellulose, the main component of the cell walls of algae and plants. It also has an unusually high electrical potential relative to the seawater around it, although no one is sure why.

And just in case you were wondering (because I know you are): yes, you can eat it, and no, it does not taste good.

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Fun Fact: on Mountain gorillas

May 19, 2022

Fun Fact: Mountain gorillas live a near-constant state of flatulence because of their diet.

Eating 20 kg a day of salad could do that to anyone. A 2020 BBC documentary using animatronic cameras recorded a family of gorillas munching on leaves, twigs, and fruit. In addition to the intestinal orchestra, they also captured the gorillas singing for their supper. In an associated study published in PLOS ONE, older male gorillas were reported to be the most likely to sing and everyone was more likely to sing for salad (aquatic vegetation, flowers, and seeds) than for bugs.

You and me both.

If you’re interested in further reading, see their 2016 paper:

For a video of the “chorus”, follow this link:

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Fun Fact: about Sphagnum moss

May 12, 2022

Fun Fact: Sphagnum moss was so important for wound dressing during World War I that someone wrote a poem about it.

The Flanders poppy (Papaver rhoeas) thrived in the battlefields of the Western Front after exploding shells brought its dormant buried seeds to the surface. It has been the symbol of remembrance for war veterans in several countries ever since, but maybe we should also be wearing sphagnum pins in November.

Sphagnum moss was used for centuries to bind wounds suffered in battle. Warriors wounded in the battle of Clontarf (1014) stuffed their wounds with moss, and there are also records of its use from the Highlanders in the battle of Flodden (1513), and both the Crimean (1853 to 1856) and Franco-Prussian (1870-1871) wars. During the first world war, the collection and production of sphagnum moss dressings began on an industrial scale. Initially, collections were made by Scottish women and children (often boy scouts and girl guides), working for long hours in cold, wet bogs. By the end of the war, collections were being made throughout Ireland, England, Canada, and the US; Britain alone was producing 1,000,000 sphagnum dressings per month.

The process of collecting, drying, and preparing dressings for WWI soldiers was pioneered by Charles Walker Cathcart, a surgeon in Edinburgh. They were very effective. Dried sphagnum can absorb up to twenty-two times its own weight of liquid, including blood, pus, and lymph, before it starts to drip. It was far superior to inert cotton wool dressings, which were both expensive and increasingly difficult to source – cotton was used to manufacture gun cotton or nitrocellulose explosives.  The preferred species for wound dressings were S. papillosum and S. palustre. Because of their ability to absorb and hold liquids, sphagnum could also be used as surgical swabs and cushions that kept beds dry while wounds were being irrigated. Under field conditions, I can imagine that a dry bed was a good bed.

In addition to its absorptive power, Sphagnum also has antiseptic properties thanks to the pectic polysaccharides (sphagnan) contained in their cell walls. Recent research from Scandinavia (where sphagnum is used to pack fresh fish), suggests the antiseptic properties are driven by the ability of sphagnum cell walls to lower the pH of their environment sufficiently to inhibit the growth of bacterial colonies.

The following poem was written by Mrs AM Smith (1917), a member of the Edinburgh Ware Dressings Supply Organisation:

The doctors and the nurses

Look North with eager eyes,

And call on us to send them

The dressing that they prize

No other is its equal—

In modest bulk in goes,

Until it meets the gaping wound

Where the red life blood flows,

Then spreading, swelling in it’s might

It checks the fatal loss,

And kills the germ, and heals the hurt-

The kindly Sphagnum Moss

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Fun Fact: Plants and stress

May 5, 2022

Fun Fact: Your distressed house plants are living out a silent horror movie.

A team of researchers at Tel Aviv University has recorded “high frequency distress sounds” emitted from tobacco and tomato plants. After stressing the plants by cutting their stems and depriving them of water (rude), the researchers recorded their responses with a microphone. In both cases they found the plants emitted ultrasonic sounds between 20 and 100 kilohertz, which they suggested conveyed their distress to other plants and organisms in the immediate vicinity.

The plants seemed to respond with different intensities of sound to different sources of stress. The team observed that tobacco plants “screamed” louder when they were deprived of water than when they had their stems cut. They believe that listening for sounds emitted by plants could help with precision agriculture and identify problems with crops.

If you’re interested in more reading, their paper can be found here:

But take it with a grain of salt… or a tablespoon because it was not published in a peer-reviewed journal.

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Fun Fact: Plants in Traffic

April 28, 2022

Fun Fact: Plants hate being stuck in traffic.

It’s easy to understand the ecological damage animals suffer as a result of noise pollution, but it has been less clear how it affects plants…until now. The indirect effects are obvious. Flowering species depend on pollinators and fruit-bearing species need animals to disperse their seeds. If the noise is a problem for their animal partners, botanical counterparts will also suffer. A recent study by Dr. Ghotbi-Ravandi, a botanist at Shahid Beheshti University in Tehran, has shown that plants are also directly affected by noise.

A number of experiments have shown that plants can sense ultrasound waves as they are struck by them, but this isn’t quite the same as urban noise pollution. In their lab, Dr. Ghotbi-Ravandi and his team grew two species that are commonly found in urban environments: French marigolds (Tagetes patula) and scarlet sage (Salvia splendens). Once mature, the plants were divided into two groups. One was exposed to 73 decibels of traffic noise for 16 hours a day, and the other was left to grow in silence. After just 15 days all of the plants in the noisy group were suffering. Two chemical compounds (hydrogen peroxide and malondialdehyde) that are indicators of stress in plants were found at much higher levels (2 to 3 times) in the group exposed to the traffic noise. Two stress hormones (jasmonic acid and abscisic acid) which are normally produced to fend off insect attacks and deal with harsh environmental conditions, were also elevated, and a range of hormones normally associated with healthy growth and development were present at significantly reduced levels in the plants exposed to the noise.

The vibrations generated by traffic noise bothered the plants in the study enough to trigger stress responses that are not much different than if they had been exposed to drought, high salinity, or heavy metals in their soil. . I guess we’ll have to call it “road sage” now…

If you’re interested in more reading, see their paper: Z.H. Kafash, Khoramnejadian S., Ghotbi-Ravandi A.A., Dehghan S.F. 2022. Traffic noise induces oxidative stress and phytohormone imbalance in two urban plant species. Basic and Applied Ecology. Volume 60. Pages 1-12.

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Fun Fact: Flower Petals

April 14, 2022

Fun Fact: Roman emperor Heliogabalus (203 – 222 AD) once dropped so many flower petals on his dinner guests that they drowned.

While we slowly get back to socialising, one might feel a twinge of anxiety at the idea of hosting a get-together. But don’t worry, it will never go as poorly as this one did:

It was such a disastrous event that someone commissioned a painting about it 1,600 years later. The Roses of Heliogabalus was painted in 1888 by Anglo-Dutch artist Sir Lawrence Alma-Tadema and depicted the young emperor hosting a banquet. The original account of the (likely exaggerated) story from Historia Augusta described a false ceiling that fell away to release a fluttering and then a torrent of violet petals. Alma-Tadema, apparently a student of floriography, decided that roses would be more appropriate. Violets represent faithfulness and modesty according to the Victorian ‘language’… none of that here.

Since roses were out of season at the time and every petal needed to be perfect, fresh roses were shipped in weekly from the south of France during the four months it took to complete the painting. A simpler solution might have been to wait until spring, but who am I to judge. Artists can be a prickly bunch.

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Fun Fact: Foxfire

April 7, 2022

Fun Fact: The controls of the first combat submarine were illuminated by mushrooms.

The submersible, named “Turtle” was invented by Yale College undergrad David Bushnell in 1775 and has a documented record of use in combat during the American Revolutionary War. The design allowed the operator to affix an explosive charge to the hull of a ship and tootle away (at a max speed of 3 mph) before the charge exploded. It was also the first submersible to use water as ballast, the first to be equipped with a breathing device, and the first to demonstrate that gunpowder could be exploded underwater. It also used foxfire from bioluminescent fungi to illuminate the needles on its internal instruments so that they could be read in the dark.

Foxfire (derived from the French ‘faux’ for false) is the bioluminescence created by some species of fungi. It occurs in a number of species including Panellus stipticus (below), Omphalotus olearius, and O. nidiformis. The blueish-greenish glow is attributed to luciferin, which emits light after oxidation catalyzed by the enzyme luciferase. The earliest record of foxfire is from 382 BC, by Aristotle. He described a light that, unlike fire, was cold to the touch. Depending on the species, the light emitted can be bright enough to read by. Some scholars attribute foxfire to the will-o’-the-whisp phenomenon described in English folklore, but under different names, is also part of the folklore of Scotland, Ireland, Wales, Canada, the US, Mexico, Brazil, Argentina, Columbia, Venezuela, Uruguay, Trinidad and Tobago, Bangladesh, India, Japan, China, Denmark, Finland, Sweden, Estonia, Latvia, Lithuania, Australia, and probably more… pretty much everyone.

Despite its glowing dials, Turtle was never successful in battle. The Americans thought that it reflected both their ingenuity after the fall of New York and their tendency to adopt and embrace new, sometimes radical technologies. The British made no record of it.

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