Unbe-leaf-able

 
 

Aisling Brennan takes a journey into the weird and wonderful world of plants.


FROM the massive to the deadly, as well as the smelly to the just plain bizarre, plants have diversified and filled every ecological niche you could think of. While many of them simply photosynthesise and bloom, and do what plants do best, there’s quite a few species that dare to do more, and many of them aren’t very friendly.

Top of any list of weird plants will be carnivorous plants. Venus flytraps and pitcher plants are well known for their animal eating habits, and to be fair, what’s weirder than a plant that pulls the natural order of things up by the roots? How about sticky, dewy leaves that envelope insects and digest them over hours and days like the sundew? Or plants that enlist the help of carpenter ant colonies to clean up the remains of kills too large for even their digestive juices to handle? Maybe the bladderwort, which uses air sacs to float and sink, and eats tiny fish and invertebrates by sucking them into a vacuum trap? Or how about some species of pitcher plants, which access valuable nitrogen by acting as an attractive toilet bowl option for tree shrews (complete with shrew-sized seat), and collecting their dung?

Have I got your attention or have you just had your lunch? If you’re queasy it might be best to avoid the next few contestants on our journey to the centre of mother nature’s twisted mind. A surprising variety of different plants smell like crap. Or faeces, or rotting corpses, or any number of unpleasant things that attract pollinators and prey alike.

“On top of smelling like a dead body, the flower has no roots, stems, or leaves, and exists normally as a parasitic vine fragment”

The Rafflesia arnoldii corpse flower (or stinking corpse lily) is the largest single flower on the planet. Or is it? On top of smelling like a dead body, the flower has no roots, stems, or leaves, and exists normally as a parasitic vine fragment, and its puzzling (and not terribly efficient) habit of occasionally forming a flower up to 43cm wide has confused scientists as to whether it’s a plant, a fungus, or something even weirder.

On the subject of stinking flowers, there are many examples to choose from. The elephant-foot yam also smells like a corpse, and produces an edible fruit that is a delicacy in some places (West Bengal) but the most inferior and last resort of all yam varieties in others (Tonga).

The skunk cabbage is doubly terrible. A big, foul smelling flower in North America, specific parts of the plant were found to be edible by indigenous people. This was presumably following a drawn out Russian roulette style trial and error, as eating too much of certain parts causes severe calcium oxalate poisoning – a corrosive toxin that burns into flesh and is capable of shutting down organ systems.

Let’s leave the odorous plants behind us. Ever wondered what the plant with the coolest name is? A strong contender is the Dragon’s-Blood tree, which looks a bit like an umbrella, with a canopy near-impenetrable to light shading its roots from the desert sun. Where it gets its name though, is from the deep-red sap flowing under its bark, which can seep out and ‘bleed’ if damaged.

Trees may not seem like the weirdest of plants, but some of them take being a tree to extremes, like the largest tree ever recorded: a Coast redwood that fell in 1905, and weighed nearly 3 million kilograms. Or the Pando tree aspen colony, which is a shared root system with more than 40,000 clonal trunks that are estimated to be about 80,000 years old, and survivors of multiple ice ages and fires.

For a little more diversity look no further than Acacia species, which can warn nearby trees to become more toxic if a herbivore eats its leaves, or strike up a room-and-board deal with massive ant colonies in exchange for swarmy, bitey protection. And that’s on top of having massive thorns.

“Eating too much of certain parts causes severe calcium oxalate poisoning – a corrosive toxin that burns into flesh and is capable of shutting down organ systems”

Some plants look weird, some plants smell strange, some are just plain wacky, like Lithrops species, which survive by pretending to look like rocks, or the 2000 year old 2-leafed tweeblaarkanniedood (say it fast five times). And some, like the deadly New Zealand tree nettle, or blinding and necrotising Giant hogweed, are incredibly toxic and dangerous, even (and sometimes especially) to humans.

But today’s winner for weirdest plant, is the hammer orchid (which, following a trend in today’s article, smells like raw meat). The name doesn’t give much away to be honest, it simply describes the strange protruding appendage that sticks out from the flower, but that’s where it just begins. The appendage mimics the appearance of the flightless female thynnid wasp, which is known to climb on top of plants and flowers to signal to flying males that she is ready to mate. So, when a hapless male wasp sees the swaying ‘hammer’, he tends to do what males so often do best and leaps before looking, trying to pick up the ‘female’ for a good time. The problem is that this female doesn’t want to go anywhere, and before the male gets very far he’s unceremoniously dunked into a pitcher of orchid pollen.

And if he gets fooled twice, then the glorious life-cycle of the raw-meat-smelling, thynnid wasp cat-fishing orchid, gets to begin anew.

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