The Curious Case of Poop-Eating Plants

Poop. Not a subject of polite conversation. But with a six-year-old granddaughter, this is an integral part of my daily discussions—stories and jokes which feature poop, farts, and belches, and I thought nothing could get me.

But poop-eating plants did! This is one of those bizarrely strange tales from the natural world that makes me marvel at how much we don’t know.

The next time someone tells you that plants only need sunshine, nutrients from the soil and water, its time to pop out the word coprophagy. That’s the term for poop-eating. Most often it’s associated with animals—rabbits, dung beetles, and sometimes dogs. But it turns out that some plants may also be participants in this less-than-dainty buffet. Not many, mind you. It’s an exclusive club.

The pitcher plant (genus Nepenthes) is a frontrunner in this strange category. While most carnivorous plants are famous for trapping insects, some tropical species of Nepenthes have found an alternative nutrient source—bat poop. In places like Borneo, bats roost conveniently above the pitchers, and their droppings fall right in. Scientists call it a “nutritional mutualism.” The bats get shelter; the plant gets dinner. Apart from bat-poop, plants are known to eat the poop of tree shrews, lizards, and even of birds. These flowers even resemble toilets—all the better to catch the poop as it falls.

These plants don’t actually chomp up poop. Rather, they have evolved to extract nutrients from faeces, often via mechanisms like sticky leaves, enzymes, and old-fashioned decomposition. Some even form alliances with fungi or microbes to get the job done.

But why on earth would a plant choose poop? It’s a matter of efficiency. Poop, especially from animals like bats and tree shrews, is rich in nitrogen and phosphorus—two nutrients that are vital for plant growth but maybe in short supply in nutrient-poor soils where many of these carnivorous plants grow. Insects provide these too, but poop is like a ready-made fertilizer packet, no hunting required. Poop offers a shortcut—already digested, already broken down. Though the comparitive nutritive values have not been rigourously tested, it is believed that poop is more nutritious.The bats roost above the pitchers, do their business, and the plant simply absorbs the nutrients through specialized enzymes or microbes that help break things down. Also, insects are scarce on tropical peaks above 2,200 meters, so poop provides a good alternative source.  In fact, scientists are finding that some carnivorous plants are evolving from eating bugs to eating poop! Some pitcher plants have even evolved shapes and scents to attract the animals specifically for their droppings!

Are there any Indian coprophagic plants?

Yes indeed! North East India is home to several species of pitcher plants or Nepenthes. Recent studies suggest that some species in the Nepenthes family (including those found in Southeast Asia) are more than happy to lap up the occasional faecal nutrient.

The Western Ghats, another biodiversity hotspot, also hosts a variety of unusual plants, including some that partner with fungi to decompose animal droppings in the soil. While not technically “eating” poop in the way a pitcher plant might, these interactions are still part of the larger cycle of nutrient recycling—with poop part of this circle of life.

So, the next time you see a lovely green pitcher in a botanical garden or on a damp forest trek in the North East, give it a respectful nod. It might be doing more than just sitting pretty. It might be part of a brilliant, bat-poop-powered system we’re only just beginning to understand.

Well, I know that after this story, Botany is definitely going to be my granddaughter’s favourite subject! Who knew botany could be this…entertainingly gross?

–Meena

Picture: http://www.kew.org/read-and-watch/poo-plants

Musa Sapientum: The Fruit of Wise Men

On 10 April 1633, the window display of the shop in London attracted huge crowds. It displayed a hitherto unknown, and unnamed item. The displayer Thomas Johnson, a herbalist, botanist and merchant described it thus: The fruit which I received was not ripe, but greene. This stalke with the fruit thereon I hanged up in my shop, were it became ripe about the beginning of May, and lasted until June. Each of them (the fruit) was the bignesse of a large beane some five inches long and an inch and a half in breadth. The stalk is short and like one’s little finger. They hang with their heads down, but if you turn them up, they look like a boat. The husk is easily removed. The pulp is white, soft and tender and ate somewhat like a musk melon.

What was this fruit that he so described? Hard to believe, but this was the banana! How, and from where a bunch of this mysterious fruit reached the shop remains a mystery in itself, but it is believed that most people in England had not seen a banana even by the end of the 19th century when regular imports started from the Canary Islands.

And yet, it is believed that bananas were among the oldest cultivated fruit. They probably originated in the jungles of Malaysia, Indonesia or the Philippines and some parts of India where they grew in the wild. Modern edible varieties of the banana have evolved from the two species–Musa acuminata and Musa balbisiana and their natural hybrids, originally found in the rain forests of S.E. Asia.

During the seventh century AD their cultivation spread to Egypt and Africa. The fruit may have got its name from the Africans, as the word is derived from ‘banan’ the Arab word for ‘finger’.  A cluster of bananas is called a ‘hand’.

Bananas were first introduced to the Western world when Alexander the Great discovered them during his conquest of India in 327 B.C. The fruit spread through Africa and was eventually carried to the New World by explorers and missionaries. Bananas started to be traded internationally by the end of the fourteenth century.

However it was not until the late mid-1800s that bananas became widespread on the North American continent. The first enterprise to import bananas into the US was the Boston Fruit Company.

Carl Linnaeus, the 18th century Swedish botanist whose work led to the creation of modern-day biological nomenclature for classifying organisms was the first person to successfully grow a fully flowered banana tree in the Netherlands.

The development of railroads and technological advances in refrigerated maritime transport subsequently enable bananas to become the most traded fruit in the world.

Today bananas are grown in more than 150 countries, and it is widely believed there are more than 1,000 types of bananas produced and consumed in the world. The most common and commercialized type is the Cavendish banana which makes up around 47 of global banana production. This is a high-yielding variety which is also less damage-prone and more resilient in case of natural disasters.

Although we generally describe it as a banana ‘tree’, technically this is not a tree. Bananas, botanically, are considered to be big herbs, because they do not have a woody stem or trunk which is one of the characteristics of a tree. Instead they have a succulent stalk or pseudostem which begins as a small shoot from an underground rhizome and grows upwards as a single stalk with a tight spiral of leaves wrapped around it. Banana leaves are extensions of the sheaths.

To add to the confusion, the banana ‘fruit’ as we call it, is botanically a berry! While we associate berries with small, squishy fruit that is picked off plants, the botanical definition refers to any fruit that develops from a flower containing a single ovary, has a soft skin and a fleshy middle, and contains several seeds. Bananas tick off all these boxes and are thus technically berries!

The botanical kin of bananas include tomatoes, grapes, kiwis, avocados, peppers, eggplants and guavas. Botanically all berries!

Bananas have long been high on the list of ‘super foods’, endorsed from all schools of health from Ayurveda to the newest ‘wellness’ trends. Its versatility was noted even by Linnaeus who envisaged its numerous medicinal values. The banana is literally ‘wholesome’ from A to Z! It is the panacea for all ills from acidity and anaemia, through cramps, depression, mood elevation, PMS, stress relief, and more, all the way to bringing in some zing to tired bodies and minds! Even the banana peel with its blend of acids, oils and enzymes has multiple uses from healing wounds to polishing shoes!

And the banana is a wonderful example of Nature’s perfect packaging. The artful positioning of the individual bananas to form a beautiful cluster or ’hand’ arrangement which can be hung; the tamper-proof skin that protects the soft and perishable flesh within; the nifty top opening that allows for an easy peeling back; and after all that, a covering that does not add to the litter but silently biodegrades to merge back into the soil. No wonder its botanical name is Musa sapientum: the fruit of wise men.

In India the mango always lays claim to being the king of fruits; the solid trustworthy banana is taken much for granted, as it does not make a dashing seasonal appearance and compete for awards of the most varieties and the best of them all. And yet this is the comfort food that is usually on hand, and one that almost every person can afford. It certainly was my father’s favourite, and now is the favourite of his great grandson who endorses Daddy’s maxim of Sabse Achchha Kela (banana is  bestest!)

Why this sudden paean to the banana? Well, I discovered that in America, the third Wednesday of April is celebrated as National Banana Day every year (reason for this undiscovered). I decided to join the celebrations this year!

Bananas were first brought to the United States in 1876, for the Philadelphia Centennial Exhibition. The exotic fruits were wrapped in foil and sold for 10¢ apiece (roughly $1.70 in today’s dollars).

While the mango always lays claim to being the king of fruits, the solid trustworthy banana is taken much for granted, as it does not make a dashing seasonal appearance and compete for awards of the most varieties and the best of them all!

The Banana was my father’s favourite fruit. He always used to say “sabse achha kela!” “Banana is the best”. So true…The scientific name for banana is musa sapientum, which means “fruit of the wise men.”

–Mamata

The Ultimate Flower-Clock

Wouldn’t it be beyond-beautiful if we had a clock which did not tell time by mundane numbers and needles, but by a particular flower blooming? Imagine if you peeped out of the window and you could look at this clock, and tell if it was 12 noon, or 1 pm or 2 pm by the flower that was blooming!

This was the kind of clock that Carl Linnaeus dreamed of.  Linnaeus’s flower clock or Horologica Floræ is a garden-plan thought up by Linnaeus that would take advantage of plants that open or close their flowers at particular times of the day, to accurately indicate the time.

As most of us would remember from school-biology, Linnaeus was the Swedish naturalist who laid down the principles for defining genera and species of organisms, and created a uniform system for naming them (the binomial nomenclature). His book, Systema Naturae (The System of Nature) consisted of only 11 pages but laid the foundations of taxonomy. It presented a hierarchical classification or taxonomy, of the three kingdoms of nature: stones, plants, and animals. Each kingdom was subdivided into classes, orders, genera, species, and varieties. All modern classification systems in biology have their roots in the Linnaean classification system which is based on similarities—for instance, Linnaeus grouped together organisms that shared obvious physical traits, such as number of legs or shape of leaves.

The Linnaean system of classification consists of a hierarchy of groupings, called taxa (singular, taxon). Taxa range from the kingdom to the species. The kingdom is the largest and most inclusive grouping. It consists of organisms that share just a few basic similarities. Examples are the plant and animal kingdoms. Then come the phylum, then the class, order, family, genus, and finally the species–the smallest and most exclusive grouping. It consists of organisms that are similar enough to produce fertile offspring together.

Linnaeus greatest contribution to science was his method of naming species. This method, called binomial nomenclature, gives each species a unique, two-word Latin name consisting of the genus name and the species name. An example is Homo sapiens, the two-word Latin name for humans, literally meaning “wise human.”

But if Linnaeus saw order in the natural world around him, he saw beauty too. In around 1748 he started thinking about the flower-clock. It builds on the fact that there are species of plants that open or close their flowers at set times of day. In his publication Philosophia Botanica, he gives 46 examples of flowering plants that are open during particular parts of the day. He brought together 43 of these under the heading Horologium Florae, or Floral Clock, arranging them in a time sequence from 3 am to 8 pm. The time at which each flower opens and closes is given in whole and half hours.

To give you a glimpse, here are a few rows from Linnaeus’ table:

Botanical nameCommon nameOpening timeClosing time
    
Tragopogon pratensisGoat’s-Beard3 a.m.
Cichorium intybus L.Chicory4–5 a.m.
Reichardia tingitana (L.) RothFalse Sow thistleby 6 a.m.10 a.m.
Taraxacum officinale WeberDandelion5 a.m.8–9 a.m.
Crepis alpina L.Hawk’s beard5 a.m.11 a.m.
Hieracium umbellatum L.Hawkweed6 a.m.5 p.m.

Though Linnaeus worked for years on this, the observations and hence selection and organization of flowers were not complete.  Linnaueus’ son Carl the Younger was given the task for completing the table so that the clock could be built. Unfortunately, Linnaeus the Younger’s floral clock was never completed, and his observations on the opening and closing of flower have not been found among his surviving papers.

Alas, no one has actually built such a clock, and it is not even clear that it is possible.  There are many practical issues to overcome. For instance, it would only function for part of the year since plants don’t flower through the year; the time shown would be indicative at best since blooming times are in a range and would vary with specifics like weather and other atmospheric conditions; many of the plants that Linnaeus observed and selected were wildflowers from Sweden and may not be found in other places, or would behave differently in other places. And then, the clock may not work at all in some seasons, if there are not enough flowers which bloom then.

Well, in this digital age, there are some ingenious people who have created an app based on the idea. They have selected 24 flowers, one for each hour that would normally flower at that time of the day or night. Floræ – Linnaeus’ flower clock app is free on appstore for Apple and iPhone.

So maybe we have make do with that, till some genious actually builds the Horologica Floræ to blow our minds!

–Meena

https://www.countrylife.co.uk/nature/curious-questions-what-is-linnaeuss-flower-clock-259032

Wikipedia

Wikimeida Commons (Picutre)