The Mimosa Pudica plant doesn't like being touched, not even lightly brushed with one finger. In fact, the plant appears to die the moment it encounters a human hand. But it isn't the only flora and fauna that likes to play the death card trick.
The Mimosa pudica (from Latin: pudica "shy, bashful or shrinking") is also called the sensitive plant or the touch-me-not. Native to South America and Central America, the plant is highly prized for its quirky action; it plays dead whenever it is touched.
The plant's instinctive response was captured in this video posted by YouTube user angeldanielmx. Although it was first uploaded back in 2008, the video is only just now going viral having amassed almost 700,000 hits.
The film captures the plant's response to being touched, first by the palm of the hand and then by an individual finger tip. Its reaction is instantaneous and remarkably astonishing.
According to the Union County College (UCC) Biology Department, the Mimosa pudica is remarkable because of its:
Nyctinastic movements: in the evening the leaflets fold together and the whole leaf droops downward until sunrise and its Seismonastic movements: touching the leaves, or shaking the plant, or slight warming of the leaves, or chemical and electrical stimuli, or subjecting the plant to a lack of water, will cause the leaflets to fold together and the whole leaf to droop downwards temporarily.
Like the shamrock, its foliage closes at darkness then reopens in light, but there is still no concrete theories as to why the Mimosa reacts as it does. One strong suggestion is the Mimosa's reaction is a survival mechanism and wilted leaves have less appeal to herbivores over more vibrant ones.
If accurate, this survival instinct in play is fascinating to watch, but certainly not novel amid the plant and animal kingdoms. In fact several species of flora and fauna play the death card for a variety of reasons, but all are aimed at ensuring their survival.
Everyone has heard of the carnivorous Venus flytrap, a plant that cleverly catches and then digests its prey, typically insects. Less common, is the species known as corpse flowers.
There is no scented bliss to be had here. Corpse flowers (hence the name) emit the odor of rotting flesh to attract insects. One of these, the Rafflesia, is the state flower of Indonesia. According to Environmental Graffiti.com, the Rafflesia flower is also a parasite that latches onto vines and then grows inside them. With no roots of its own, it emits the stench of rotting decay to attract flesh eating flies for pollination purposes.
Some animals also excel at 'playing possum.' The Hog-nosed Snake for example, likes to roll onto its back and appear dead whenever threatened by a predator:
But playing dead serves a dual purpose for these animals and plants. Not only does it make the critter appear less appetizing, it also curbs the killing and chase instinct prompted by an animal in flight.
Rather than simple attraction for pollination benefits, some animals use 'apparent death' to attract prey to eat. The cichlid: Haplochromis livingstoni for example, will float on its side and wait for smaller fish to move in for the nibble. Once they commit, it's game over. No longer an easy meal, the cichlid revives with a lightning burst of speed to snatch the smaller fish as a meal says Animal-world.com.
And the incredible display of the killdeer bird, a medium-sized plover that feigns injury to protect its eggs and young, is notorious. According to Birdwatching.com, approaching the adult bird results in it suddenly developing a broken wing. As it "struggles in front of you," the website explains, the bird acts "as if it can barely walk, let alone fly."
Whether it is man or beast that attempts to investigate the injured avian, the faking bird will cleverly elude both by just staying out of reach. In the meantime, the potential predator is unwittingly led further and further away from the bird's nest. Once it believes its babes are safe, the killdeer gives a jest-filled chirp and takes to the air.
But feigning death has not been associated purely with plants and animals. In 2009, a paper published in the Proceedings of the Royal Society B, demonstrated the adaptive significance of playing possum in animals and humans. The act itself was deemed a 'selfish behavior.'
Takahisa Miyatake, lead author and professor in the Laboratory of Evolutionary Ecology at Okayama University said that "Death-feigning prey increase their probability of survival at the expense of more mobile neighbors."
And, suggests MSNBC, human beings could also fit the scenario. Feigning death "can lead to the killing of one's friends and relatives" MSNBC said, with people who play dead surviving, "while their fleeing colleagues usually aren't so lucky." Professor Miyatake added that in reference to war, or war-like conditions, it is a good possibility. "We can imagine such a (death-feigning) person might survive more," he said.