A botanical chameleon

One of the things I love most about science is its capacity to astonish us.

You can be really knowledgeable in a field, and then the natural world slings a curve ball at you and leaves you amazed.  Sometimes these unexpected twists lead to profound leaps in our understanding -- an example is the discovery of the parallel magnetic stripes in igneous rocks along the Mid-Atlantic Ridge leading to the theory of plate tectonics -- but sometimes it's just a fascinating bit of scientific trivia, one of those little things that makes you smile in a bemused sort of way and say, "Science is so cool."

I had a moment like that yesterday.  I taught biology for 32 years and have been interested in plants -- especially tropical plants -- a great deal longer than that.  I have a fine collection of tropical plants, currently jammed into my greenhouse so tightly that I can barely walk through it because the ones who spend the summer on my deck have to be tucked away in a warm place during our frigid winters.  I have bromeliads, cacti, three species of ginger, four different kinds of angel's trumpet (one of which got to be seven feet tall this past summer, and sometimes had twenty giant, peach-colored flowers all blooming at once), a fig tree and a lime tree that produce every year, and two species of eucalyptus.

Among others.

While I wouldn't call myself an expert when it comes to tropical plants, I'm at least Better Than The Average Bear.  So I was startled to run, quite by accident, into an account of a species I had never even heard of -- and even more startled when I found out how truly bizarre and unique this plant is.

It's called the "chameleon vine," and its scientific name is Boquila trifoliolata.  It belongs to a small and rather obscure family of dicots called Lardizabalaceae, which contains forty species found in two places -- southeast Asia and western South America.  (How a group of plants with common ancestry ended up in such widely separated locales is a mystery in and of itself; populations like this are called peripheral isolates and are a perennial puzzle in evolutionary biology.)

Boquila is one of the South American ones, and lives in southern Chile and Argentina.  It's a woody vine whose leaves are composed of three leaflets (thus the plant's species name).  Here's a picture:

[Image licensed under the Creative Commons Inao, Boquila trifoliata [sic], CC BY-SA 2.0]

It's not really much to look at, and you non-botanical types are probably tapping your fingers and saying, "So what?"  But wait till you hear what this plant can do -- and why it merits its common name of "chameleon vine."

Boquila trifoliolata has an extraordinary ability called mimetic polymorphism.  It's capable of altering its leaf shape to mimic a variety of different (unrelated) plants -- including the ones it most commonly twines up as a support.  We're not talking about small differences, either.  It can be glossy or dull, have different petiole lengths, have different leaflet sizes and shapes, and even change whether or not it has serrations or spines along the edge!

This ability, first described in a paper by botanists Ernesto Gianoli and Fernando Carrasco-Urra in Current Biology in 2014, was first attributed to genetic transfer from the host to the vine, a sort of genetic parasitism.  I'll admit that was the first explanation I thought of -- although how a plant could take up DNA from another species and only express the genes related to leaf morphology left me scratching my head a little.  But Gianoli and Carrasco-Urra were able to rule out this possibility, because Boquila can alter its leaf shape without touching the plant it's mimicking.

All it has to do is be nearby.  So it isn't a parasite at all.  The current guess is that Boquila is picking up volatile organic compounds emitted by the other plant, and those are altering gene expression, but those organic compounds have yet to be identified -- nor has any kind of specific mechanism by which that kind of alteration in phenotype could happen.

Less certain still is how it perceives those specific traits in its neighbors so it knows what genes to express, and how.

Even though we still have no idea how Boquila is managing this neat trick, the why is pretty clear.  If it's hiding amongst the foliage of another plant, herbivores can't single it out for a snack.  Gianoli and Carrasco-Urra found that when Boquila is climbing up a non-living support like a chain-link fence, herbivores actually seek it out for browsing.  But when it's camouflaged within another plant's leaves, it can avoid being seen and identified -- and, they found, browsing of its foliage dropped by as much as fifty percent.

Fascinating, isn't it?  And yet despite study, we haven't been able to figure out how the plant evolved this amazing (and apparently unique in the plant world) ability, nor what kind of information it's gleaning that might say, "Okay, time to change color and grow some spikes!"

So yet another example of how science is really freakin' cool.  It also illustrates how every new discovery opens up new avenues for investigation.  The crazy chameleon plant should make it absolutely clear that if you go into science, you'll never be done learning.

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Ephemera

I think a lot of people -- and I'm very much including myself in this -- sleepwalk through a lot of our lives.

We focus on what's right in front of us, often skewed by what we expected to see or hear.  That inattentional blindness is what makes eyewitness testimony so fundamentally flawed; combine the fact that most of the time, we aren't even seeing what's around us, with the plasticity of human memory and it's a wonder eyewitness accounts are even admissible in a court of law.

I still remember the first time I was shown the most stunning example of inattentional blindness I've ever run across, in a college psychology class.  The video was set in a hotel lobby, where a young man was seated behind a table draped with a cloth.  He had a clipboard, and politely asked each passerby if they'd mind taking a brief survey.  When someone said yes, he handed them the clipboard, simultaneously "accidentally" dropping the pen on the floor behind the table.  He smiled, said, "Sorry," and ducked down to get the pen...

... but the young man who came back up was a totally different person.  They looked nothing alike.  One was blond, the other brunette; one had facial hair, the other didn't; and so on.

Virtually no one noticed the switch.  When asked afterwards, most of the test subjects said they'd had no idea there was another man hiding under the table who took the first man's place when the pen was dropped.  A couple of them said, "I thought I was just remembering wrong."

It's one of the things that has to change when you start doing science.  In science, the key is not only to see, but actually to see what you're seeing.

Take, for example, the strange little plant called false mermaid weed (Floerkea proserpinacoides).  It's in the family Limnantheaceae, which contains only eight species, seven of which are mostly found in wet meadows in California and Oregon.  False mermaid weed, though, is thought to live in many shaded woodland habitats in North America, but is such an unassuming little thing that honestly, we're not sure what its range is.

[Image licensed under the Creative Commons cassi saari, Floerkea proserpinacoides flowering, CC BY-SA 4.0]

It's an annual (only lives a single season) and a spring ephemeral (only has above-ground visible parts in the spring), so that added to its tiny size makes it extremely difficult to spot.  It had been recorded in Vermont in 1916 by botanist Nellie Flynn, who during her lifetime described, collected, and sketched over twenty-two thousand different species of plants.  But since Flynn spotted it, no one has seen false mermaid weed in Vermont.

And not from lack of trying.  Botanists are trained to recognize plant species in the regions they study, and Vermont has been thoroughly surveyed.  But for over a hundred years, no one saw this tiny woodland plant in the state of Vermont.

Until botanist Grace Glynn rediscovered it last month.

"I sort of did a double-take and rubbed my eyes and couldn't believe I was seeing this plant," Glynn said.  "Most people thought it had been extirpated because of extreme flooding, invasive species and human development.  Its rediscovery is a sign that good stewardship by landowners and conservation organizations really can make a difference."

You have to wonder how many people walked right by this little plant without realizing its significance.  I'm sure I would have; I'm fair-to-middling at recognizing plants, but there's no reason this one would have struck me as anything special.  It was a combination of extensive training and an exceptionally good eye that allowed Grace Glynn to find it.

Unlike most of us, she actually saw what she was seeing.

"It was just amazing to touch this plant and to think, 'Oh, Nellie Flynn was probably the last person to ever touch this species in Vermont back in 1916,'" Glynn said.  "And I always think about how there are just these threads through history that kind of tie you to other botanists, and it just adds depth and richness, I think, to an already rich story."

The world is full of ephemera that we walk past every day and miss, caught up in our day-to-day struggles and locked in the bubble of our perception.  Most of us aren't trained scientists like Grace Glynn, but we all can work toward opening our eyes to what surrounds us.

Who knows what wonders we might end up seeing?

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The Lazarus flower

The adage goes, "Extinction is forever."

It's a sobering thought.  There's been talk of "de-extinction" -- using intact DNA from well-preserved fossils to resurrect, Jurassic-Park-style, extinct animals -- but so far, the research in that vein has been tentative and not particularly promising.  Plus, there are the inevitable ethical questions about bringing back woolly mammoths, passenger pigeons, and dodos into a world where their environment has changed into something they couldn't survive in anyway.  It seems like recreating a few individuals of an extinct species, then having them live out their lives in zoos, is nothing more than generating a handful of entertaining curiosities at a very great cost.

There are, however, a few species that have been declared extinct which have turned out not to be.  The most famous of these is the coelacanth, a weird-looking fish that's one of the lobe-finned fish, the fish group with the closest relationship to amphibians.  It was thought that all the lobe-fins had become extinct along with the non-avian dinosaurs during the Cretaceous Extinction 66 million years ago, but then someone caught one in the Indian Ocean.  There are, in fact, two living species of coelacanth -- the West Indian Ocean coelacanth (Latimeria chalumnae) and the Indonesian coelacanth (Latimeria menadoensis).  This long-term survival of a species that was thought to be long gone has resulted in the coelacanth being labeled a "living fossil" or a "Lazarus taxon."

There are also the ones that have been declared extinct, but that a handful of true believers -- and sometimes some scientists, as well -- are convinced are still alive.  The last thylacine, or Tasmanian wolf (Thylacinus cynocephalus), which is neither a wolf nor restricted to Tasmania, died in a zoo in 1936 -- except there continue to be sightings of purported thylacines, both in Tasmania and adjacent South Australia.  In fact, there's a Facebook group devoted to alleged thylacine sightings, which so far, have either been anecdotal, or accompanied by photos of Bigfoot-level blurriness.

Then there's the ivory-billed woodpecker (Campophilus principalis), an enormous woodpecker species that used to live in swampy regions of the North American southeast.  The last confirmed sighting was in Louisiana in 1944, but there have been sporadic reports ever since -- most, probably, of the related (but smaller) pileated woodpecker (Dryocopus pileatus).  But a friend of mine, an employee of the Cornell Laboratory of Ornithology, was part of the team sent to investigate a cluster of alleged sightings, and she was one of the people who say they actually saw one.  Now, let me add that my friend is an accomplished and knowledgeable birder, and knew what she was looking for; she, and the other members of the team, would not mistake a pileated woodpecker for this bird.  Unfortunately, the only video they got was short and of poor quality, and although she and the rest of the team have serious credibility, it still amounts to a single anecdotal report, and a lot of folks are not convinced.

All of this is just by way of introducing a discovery that should give some hope to the thylacine and ivory-billed woodpecker aficionados.  Just last week, a paper in the journal PhytoKeys described the (re)discovery of a plant in the family Gesneriaceae, a tropical group most familiar to collectors of rare houseplants -- the best-known members are the African violet (Saintpaulia spp.),  Cape primrose (Streptocarpus spp.), and gloxinia (Gloxinia spp.).

The recent discovery was in the Centinela region of southern Ecuador, in the foothills of the Andes Mountains.  Centinela has been devastated by deforestation -- by some estimates, 97% of the original old-growth rain forest has been cleared or extensively damaged -- so it's to be expected that any species endemic to the region are gone.  That's what the botanists thought about a glossy-leaved, orange-flowered plant that grew in the humid understory; it was last seen in the 1980s.  By the time it was discovered and catalogued, it was gone.

That's why they named it Gasteranthus extinctus.

And then, a couple of months ago, some botanists studying what's left of Centinela found that it wasn't extinct after all.  Here's the plant:

[Photograph by Riley Fortier]

They took lots of photographs but were careful not to disturb the few remaining plants -- nor are they telling exactly where they found them.  This same strategy was adopted by the folks from Cornell looking for the ivory-billed woodpecker; the last thing they needed was a bunch of overenthusiastic amateurs stomping about the place (and you know they would).  But it is a hopeful thought, that some of the species we thought were gone forever might still be out there somewhere.  (For what it's worth, they're keeping the name Gasteranthus extinctus, and hoping that it doesn't one day become accurate in fact.)

"Rediscovering this flower shows that it’s not too late to turn around even the worst-case biodiversity scenarios, and it shows that there’s value in conserving even the smallest, most degraded areas," said Dawson White, a postdoctoral researcher at the Field Museum in Chicago, who was the paper's lead author.  "New species are still being found, and we can still save many things that are on the brink of extinction."

So that's today's optimistic news.  Me, I'm still hoping for the thylacine.  Those things were cool.  While thus far the evidence thus far has been less than convincing, it's certainly still a possibility that it -- and some of the other species most folks have given up on -- are still alive after all.

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A flower in amber

Today's post comes to us purely from the "Okay, This Is Cool" department.

I've been fascinated with plant taxonomy since long before I knew the word.  I couldn't have been more than about seven years old when a friend of the family gave me a lovely old book by the early twentieth-century botanical illustrator F. Schuyler Mathews called Field Book to American Trees and Shrubs.  Not only did I use it to try to identify every tree in my neighborhood, I found out something about how plants are classified -- not by leaf shape (which at the time seemed to me the most logical characteristic to use) but by flower structure.  That's when I learned that beeches, oaks, and chestnuts are in the same family; so are rhododendrons, heather, blueberries, and cranberries; so are birches, alders, and hazelnuts; so, most surprisingly to me, are willows and poplars.

It was also my first introduction to how difficult the classification of organisms actually is, something I learned a great deal more about when I took evolutionary biology in college.  The standout from Mathews's book in that respect is the genus Crataegus, hawthorns, of which he lists (and illustrates with beautiful woodcuts) over a hundred species, many of which looked (and still look) exactly alike to my untrained eye.  Taxonomists argue vehemently over how particular species are to be placed and who is related to whom, although the advent of genetic analysis and cladistics has now provided a more rigorous standard method for classification.

What I didn't know, even after my umpteenth perusal of the Field Book, was that the strange and magical-sounding scientific names of plant families Mathews mentions are barely scratching the surface.  You go elsewhere in the world, all bets are off; you'll run into plants that are in families with no members at all in the United States.  An odd historical filigree is that one of the reasons the British colonizers felt so at home in northeastern North America was that the plants were familiar; oaks, ashes, beeches, birches, willows, maples, pines, and spruces are found in both places (although the exact species vary).  Go to southeast Asia, South America, or pretty much anywhere in Africa, though, and even someone well-versed in the plants of North America and western Europe might well not recognize a single species.  I found that to be the case in Malaysia -- a (very) little bit of reading about the flora of the places I visited gave me at least a name or two, but I'd say 95% of what I saw I couldn't even have ventured a guess about.

One of the many peculiar plants I saw in the rain forests of Malaysia -- I still don't know what it is, but it sure has a cool-looking leaf.

The reason this comes up is an article sent to me by a friend and loyal reader of Skeptophilia about a fossil from Myanmar that was the subject of a recent paper in The Journal of the Botanical Institute of Texas.  Encased in amber, the flower is almost perfectly preserved -- despite being just this side of one hundred million years old, a point at which the dinosaurs would still be in charge of everything for another thirty-four million years.

If it sounds like figuring out the taxonomy of modern plants is a challenge, it gets way worse when you start looking at plant fossils.  Not only do we not have living plants to analyze genetically, often what we're having to judge by is what's left of a leaf or two.  Fortunately, in this case what the researchers have is a preserved flower -- remember that flowering plants are classified by flower structure -- and that was enough to convince them that they were not only looking at a previously unrecorded species, but a previously unrecorded genus -- and possibly a whole new family.

The flower of the newly-named Micropetasos burmensis [Image by George Poinar of Oregon State University)

Most fascinating of all, the researchers aren't even sure how Micropetasos fits into known plant systematics.  The paper says about all we can say so far is that it seems to belong to the clade Pentapetalae -- which doesn't narrow it down much, as that same clade contains such distantly-related plants as roses, asters, cacti, cucumbers, and cabbage.

Long-time readers might recognize the name of the lead author of the paper -- George Poinar.  This isn't the first time he's pulled off this kind of botanical coup.  About a year and a half ago, I wrote about another of Poinar's discoveries in Burmese amber, a little flower called Valviloculus pleristaminis, which also was of uncertain placement amongst known plant families.  Amazing that in bits of fossilized tree sap we can find remnants that allow us to piece together the flora of the Cretaceous Period.

Of course, what it always brings up is the elegiac thought that however many fossils we find, the vast majority of species that have existed on Earth left no traces whatsoever that have survived to today.  If we were to take a time machine back a hundred million years, Micropetasos and Valviloculus we might perhaps recognize from Poinar's work; but there would be thousands more that are completely unfamiliar.  The lion's share of prehistory is unknown -- and unknowable.

But at least we have one more little piece, a tiny flower in amber.  When it was growing, there were triceratopses and T. rexes stomping around, and our closest ancestors were small, rodent-like critters that still had tens of millions of years of evolution before they'd even become primates.  That we can have any sort of lens into that distant, ancient world is astonishing.

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A botanical mystery

One of the most pernicious tendencies in human thought is our arrogance.  The attitude that we know all there is to know, understand the universe, have it all figured out, has led to more oversights, blunders, and outright idiocy than anything else I can think of.

What's striking is how often our intuition about things turns out to be wrong.  Consider, for example, the following question: of all the species currently alive on Earth, what percent of them are known to science -- identified, observed, collected, or studied?

The best estimate we have, from a 2011 study that appeared in PLoS Biology, blew my mind, and as a 32-year veteran of teaching biology, I was ready for an answer lower than my expectation.  You ready?

Fourteen percent.

The study estimated the total number of species on Earth at 8.7 million, 86% of which are unknown to science.  This is staggering.  We are fooling around with our climate and ecosystems, bulldozing our way through our own living space, and potentially destroying millions of species we didn't even know existed.

To be fair, our ignorance about the organisms we share the planet with is at least in part not our fault.  If, like me, you live in a comfortable home with amenities and no particular need to venture off into the wilderness, it would be easy to think that our familiar surroundings are all there is.  The truth is a little humbling, and far more interesting.  I remember my first trip to Hawaii, back in 2003, when we spent our time on the lovely island of Kauai.  While we were there, we took a boat trip out to the Na Pali Coast, a stunning terrain that has a few narrow sandy beaches, but almost immediately beyond them wrinkles up into mountains that are in places damn near vertical.

Carol and I at Na Pali

The guide on the boat told us something that I found astonishing; large parts of Waimea Canyon and Koke'e Parks, which lie inland from Na Pali, are completely unexplored.  Not only is it too steep for roads to be built, you can't even land a helicopter.  Hiking might be possible, but it's densely forested.  The combination has made the interior of these parks one of the few places in the United States where we can say with fair confidence that no human being has ever stood.

Add to that the fact that even more unexplored than some of the remote terrestrial regions are the deep oceans.  I've heard it said we know more about the terrain of the Moon than we do about the floor of the deep ocean -- I don't know if that's true, but it sure sounds plausible.

I'd like to consider, though, a more positive thought; that our lack of knowledge of other species on Earth means there is a lot out there that we could still potentially learn.  And sometimes that happens through unexpected channels.  In fact, the reason this whole topic comes up is because of an article last week in Atlas Obscura about a British botanist and biological artist named Marianne North (24 October 1830-30 August 1890), who traveled all over the world painting native plants in intricate detail -- and who captured an image of at least one plant nobody could identify.

The painting in question was made in Sarawak, one of two states of Malaysia that are on the island of Borneo.  Sarawak is a bit like Kauai; inhabited at the perimeter, but with an inland of rugged terrain and dense, nearly impenetrable forest.  Well, this kind of thing didn't stop North, who made some exquisite paintings of plants in Sarawak, including this one:

[Image is in the Public Domain]

The plant with the blue berries was unidentified -- some botanists thought it might be a member of the tropical genus Psychotria (in the coffee family, Rubiaceae).  But something about that didn't ring true.  None of the 1,582 catalogued species of Psychotria has blue berries -- all the known ones are red or pink -- and the arrangement of the leaves didn't look quite right.  So either (1) this one was an anomaly, (2) North painted the plant inaccurately, or (3) the identification was wrong.

Option (1) was a little far-fetched, but not outside the realm of possibility.  Option (2) struck most knowledgeable people as outright impossible; North was known for her absolute painstaking attention to minute detail.  So botanist and illustrator Tianyi Yu decided (3) had to be correct.  But how to find a single species of plant in an overgrown wilderness on the island of Borneo, which had avoided detection by other scientists for over a century?

Yu had a brainstorm; maybe it hadn't completely flown under the radar.  He decided to spend some time in the herbarium at Kew Gardens.  If you are ever in England, Kew is a must-see; it is home to one of the most amazingly complete collection of plants in the world, and is also stunningly beautiful, especially in spring and summer.  The herbarium contains collections of preserved plants stretching back to its founding in the middle of the nineteenth century, and currently houses over eight million specimens.

So saying it was a needle in a haystack is an understatement.  Yu had one thing going for him; North had been not only a meticulous artist, she was also conscientious about writing down where her paintings had been made.  This one was labeled "Matang Forest, Sarawak," and since the Kew specimens are catalogued not only by species but by location, it significantly narrowed down Yu's search.

And he found it.  A sprig of it was collected in 1973 and sent back to Kew, but was unidentified.  Yu studied both the specimen and North's painting, and concluded that it was a member of the genus Chassalia -- also in Rubiaceae, so the guess of Psychotria hadn't been that far off.

Further analysis by botanists confirmed Yu's surmise.  As the person who identified it as a previously-unrecorded species, Yu was given the honor of naming it.

And last year, it went down in the taxonomic records as Chassalia northi, in recognition of Marianne North's contributions to the field of botany.

So out there on the island of Borneo is a little shrub with white flowers and blue berries that we now have a name for because of a nineteenth-century adventurer/scientist/artist, a happenstance collection from 1973, and a diligent modern botanist determined to put the pieces together.  Just showing that we can still pick away at the sphere of our own ignorance -- but only if we are first willing to admit that there is a lot we still don't know about the world we live in.

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The mystery from Manu

So much of the damage we've done to the planet hasn't been deliberate destructiveness; it's been due to our carelessly stomping about the place.  We've long had the attitude that resources will never run out, that we can get away with doing whatever we want with no consequences, that nature will rebound like it always does.  There's little awareness of the absolute fragility of it all.

The "bull in a china shop" metaphor seems all too apt.

Of course, that mindset does require a good dollop of willful ignorance.  Just two weeks ago, the United States Fish and Wildlife Service declared that 22 species in the US that were previously classified as critically endangered are now officially considered extinct.  The most famous of them is the Ivory-billed Woodpecker, the largest woodpecker species native to North America, victim to habitat loss as the wetland forests where it lived were drained, the trees felled for lumber.  A full nine of the 22 are bird species endemic to Hawaii, eight of them part of the unique group called Hawaiian honeycreepers that were decimated by the double whammy of habitat loss and susceptibility to avian malaria, carried by the introduced Asian tiger mosquito.

So to think "everything's just fine" you have to make a practice of not paying attention.

One of the problems is that in some of the most vulnerable places in the world, species are disappearing before they're even identified and studied.  Take, for example, the species of tree native to the Amazon basin of Peru that was first seen by scientists in 1973 -- and that has just now been classified and named.

Robin Foster of the Smithsonian Tropical Research Institute was the one who noticed it, while walking in Manu National Park -- and despite a thorough knowledge of Amazonian flora, he couldn't figure out what it was.  "When I first saw this little tree, while out on a forest trail leading from the field station, it was the fruit -- looking like an orange-colored Chinese lantern and juicy when ripe with several seeds -- that caught my attention," Foster said.  "I didn't really think it was special, except for the fact that it had characteristics of plants in several different plant families, and didn't fall neatly into any family.  Usually I can tell the family by a quick glance, but damned if I could place this one."

So Foster sent a branch of the plant to the Field Museum of Chicago, where it sat in the herbarium for almost fifty years.  When DNA analysis became de rigueur for doing taxonomy, back in the 1990s, researchers tried extracting DNA from the dried leaves -- unsuccessfully.  Then last year, scientist Patricia Álvarez-Loayza, who is part of the team that studies the ecosystem in Manu National Park, found a living specimen of the tree, and this time the DNA extraction worked.

Aenigmanu alvareziae

The results were a shock to botanists, because it showed beyond any question that the little tree belonged to an obscure tropical family called Picramniaceae, made up of 48 (now 49) species native to northern South America, Central America, and the Caribbean, but not common anywhere.  "When my colleague Rick Ree sequenced it and told me what family it belonged to, I told him the sample must have been contaminated.  I was like, no way, I just couldn't believe it," said Nancy Hensold of the Field Museum, part of the team that studied the plant and finally identified its affinities.  "Looking closer at the structure of the tiny little flowers I realized, oh, it really has some similarities, but given its overall characters, nobody would have put it in that family." 

The plant was christened Aenigmanu alvareziae -- the genus name means "mystery from Manu," while the species name honors Patricia Álvarez-Loayza, who found the living specimen that helped to place the species.

What strikes me about this whole story is how easily the branch of this little tree could have been forgotten in the herbarium, or the plant itself overlooked completely.  The Amazon is a big place, large swaths of which are unexplored.  While one odd plant species may not seem all that important, this does give us a sense of the extent to which we're blundering around damaging living ecosystems without even understanding them fully.  "Plants are understudied in general," said Robin Foster, the first scientist who noticed Aenigmanu back in 1973.  "Especially tropical forest plants.  Especially Amazon plants.  And especially plants in the upper Amazon.  To understand the changes taking place in the tropics, to protect what remains, and to restore areas that have been wiped out, plants are the foundation for everything that lives there and the most important to study.  Giving them unique names is the best way to organize information about them and call attention to them.  A single rare species may not by itself be important to an ecosystem, but collectively they tell us what is going on out there."

Conservation isn't some kind of academic game, and rare species shouldn't just be of interest to the taxonomists.  We need to understand on a visceral level that you can't pull threads out of the tapestry of life without the entire thing coming unraveled.  Chief Seattle said it best, back in 1854: "The Earth does not belong to man; man belongs to the Earth.  This we know.  All things are connected like the blood which unites one family...  Whatever befalls the Earth befalls the sons of the Earth.  Man did not weave the web of life; he is merely a strand in it.  Whatever he does to the web, he does to himself."

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During the first three centuries C.E., something remarkable happened; Rome went from a superpower, controlling much of Europe, the Middle East, and North Africa, to being a pair of weak, unstable fragments -- the Western and Eastern Roman Empires --torn by strife and internal squabbles, beset by invasions, with leaders for whom assassination was the most likely way to die.  (The year 238 C.E. is called "the year of six emperors" -- four were killed by their own guards, one hanged himself to avoid the same fate, and one died in battle.)

How could something like this happen?  The standard answer has usually been "the barbarians," groups such as the Goths, Vandals, Franks, Alans, and Huns who whittled away at the territory until there wasn't much left.  They played a role, there is no doubt of that; the Goths under their powerful leader Alaric actually sacked the city of Rome itself in the year 410.  But like with most historical events, the true answer is more complex -- and far more interesting.  In How Rome Fell, historian Adrian Goldsworthy shows how a variety of factors, including a succession of weak leaders, the growing power of the Roman army, and repeated epidemics took a nation that was thriving under emperors like Vespasian and Hadrian, finally descending into the chaos of the Dark Ages.  

If you're a student of early history, you should read Goldsworthy's book.  It's fascinating -- and sobering -- to see how hard it is to maintain order in a society, and how easy it is to lose it.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

The natural pharmacy

A couple of weeks ago, we looked at the discovery and decipherment of a codex written in Nahuatl, one of the languages spoken by the Aztecs (and still spoken in central Mexico).  The study highlighted the fact that language is one of the most critical pieces of culture, embodying a unique way of describing the world.  When languages disappear, that perspective is forever lost.

It's even worse than that, according to another study, that appeared in Proceedings of the National Academy of Sciences a couple of months ago.  In "Language Extinction Triggers the Loss of Unique Medicinal Knowledge," authors Rodrigo Cámara-Leret and Jordi Bascompte of the University of Zürich look at the role of language in preserving information about medicinal plants -- information that might well be encoded in only a single one of the estimated 6,500 languages currently spoken on Earth.

Cámara-Leret and Bascompte considered indigenous languages in three places -- New Guinea, Amazonia, and North America -- lining up those languages with databases of medicinal native plants.  Specifically, they were looking at whether the knowledge of the medicinal value of native flora crossed linguistic boundaries, and were known (and used) in the cultures of the speakers of different languages.

Some, of course, were.  The use of willow bark as an analgesic was widely known to Native Americans throughout the eastern half of North America.  The sedative nature of poppy sap was also widespread, and has a long (and checkered) history.  (It's no coincidence that these two plants produce compounds -- aspirin and morphine, respectively -- that are part of the modern pharmacopeia.)

Illustration and uses of mandrake (Mandragora officinarum) from Dioscurides's De Materia Medica (7th century C.E.) [Image is in the Public Domain]

But what about the rest of the myriad species of medicinal plants that have been catalogued?  What Cámara-Leret and Bascompte found is simultaneously fascinating and alarming.  They looked at 12,495 species of medicinal flora native to the regions they studied, and found that over 75% of them were only named and known as pharmacologically valuable in a single language.

Worse, the researchers found that there was a correlation between the languages with the rarest medicinal knowledge, and how endangered the language is.  "We found that those languages with unique knowledge are the ones at a higher risk of extinction," Bascompte said, in an interview with Mongabay.  "There is a sort of a double problem in terms of how knowledge will disappear."

That knowledge isn't purely of interest to anthropologists, as a sort of cultural curiosity.  Consider how many lives have been saved by quinine (from the Peruvian plant Cinchona officinalis, used in treating malaria), vincristine (from the Madagascar periwinkle, Catharanthus rosea, used in treating leukemia and Hodgkin's disease), digoxin (from the foxglove plant, Digitalis purpurea, used for treating heart ailments), taxol (from the Pacific yew, Taxus brevifolia, used in treating a variety of cancers), and reserpine (from the south Asian plant Rauvolfia serpentina, used in treating hypertension).  And that's just some of the better-known ones.  The whole point of the Cámara-Leret and Bascompte study is that the majority of pharmacologically-useful plants aren't known outside of a single indigenous ethnic group -- and when those languages and cultures are lost or homogenized into the dominant/majority culture, that information is lost, perhaps forever.

"There is life outside English," Bascompte said.  "These are languages that we tend to forget—the languages of poor or unknown people who do not play national roles because they are not sitting on panels, or sitting at the United Nations or places like that.  I think we have to make an effort to use that declaration by the United Nations [the UNESCO decision that 2022 to 2032 will be the "Decade of Action for Indigenous Languages"] to raise awareness about cultural diversity and about how lucky we are as a species to be part of this amazing diversity."

I can only hope that it works, at least to slow down the cultural loss.  It's probably hopeless to stop it entirely; currently, the top ten most common first languages (in order: Mandarin, Spanish, English, Hindi, Arabic, Portuguese, Bengali, Russian, Japanese, and Punjabi) account for almost fifty percent of the world's population.

The remaining 6,490 languages account for the other half.  

I understand the drive to learn one of the more-spoken languages, from the standpoint of participation in the business world (if that's your goal).  You probably wouldn't get very far international commerce if you only spoke only Ainu.  But the potential for losing unique knowledge from language extinction and cultural homogenization can't be overestimated.  Nor can the purely practical aspects of this knowledge -- including the possibility of life-saving medicinal plants that might only be recognized as such by a single small group of people in a remote area of New Guinea. 

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Like graphic novels?  Like bizarre and mind-blowing ideas from subatomic physics?

Have I got a book for you.

Described as "Tintin meets Brian Cox," Mysteries of the Quantum Universe is a graphic novel about the explorations of a researcher, Bob, and his dog Rick, as they investigate some of the weirdest corners of quantum physics -- and present it at a level that is accessible (and extremely entertaining) to the layperson.  The author Thibault Damour is a theoretical physicist, so his expertise in the cutting edge of physics, coupled with delightful illustrations by artist Mathieu Burniat, make for delightful reading.  This one should be in every science aficionado's to-read stack!

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

The strangest flower on Earth

Anyone know what the world's largest flower is?

Chances are, some of you know that honor goes to the bizarre Indonesian species Rafflesia arnoldi, which produces flowers that can get to be 120 centimeters across.  Not only are they huge, they are (1) really weird-looking, and (2) smell like rotting meat in order to attract the flies that pollinate them.

Rafflesia arnoldi  [Image licensed under the Creative Commons ma_suska, Rafflesia sumatra, CC BY 2.0]

The first time I saw a photograph of this plant, I was immediately reminded of the Lost in Space episode "Attack of the Monster Plants," which was a real favorite of mine when I was a kid, not only because who wouldn't love a show about monster plants, but because Judy Robinson was in peril during this episode and to say I was madly in love with Judy Robinson is rather an understatement.

Be that as it may, the reality of Rafflesia is almost as weird as Judy's spaceship-fuel-eating alien plants.  The flower is enormous but the rest of the plant is minuscule, only a thin ribbon of translucent tissue that punctures the roots of vines of the rainforest genus Tetrastigma, getting all its nutrients from the host plant rather than from photosynthesis.  The only time any part of the plant is above ground is when it's flowering.  After that, the flowers wither, the fruits containing thousands of nearly microscopic seeds that are thought to be dispersed when tree shrews eat the fruit and poop out the seeds somewhere else.  But the plant's rarity, and the fact that during most of its life cycle you could walk right by it (or more likely, over it) without knowing, not that much is known for sure.

Another thing that's surprising about the family (Rafflesiaceae) is that its nearest relatives are euphorbias -- which include a huge range of plants united by having tiny, insignificant flowers and milky toxic sap and looking absolutely nothing like Rafflesia.  A number of euphorbs look superficially like cacti, with reduced or absent leaves and sharp spines, but the milky sap and inconspicuous flowers would clue you in to the fact that the similarities are due to convergent evolution.  The most familiar euphorb is the poinsettia -- the bright red, pink, or cream-colored parts are not actually petals but modified leaves.  (The flowers themselves are the little b-b sized bits at the center.)

So what this shows is that to figure out evolutionary relationships, you can't rely on what things look like.  As odd as it is, the spiky candelabra spurge (Euphorbia ingens) is a cousin of the bizarre Rafflesia.

If all that isn't weird enough, consider a study that just came out a couple of weeks ago in Current Biology that looked at another member of Rafflesiaceae, the genus Sapria.  (They're very similar to Rafflesia, differing only in a few not-very-significant botanical details.)  This study did an extensive analysis of the genetics of Sapria, and found something bizarre; during its descent from its euphorbia-like ancestors, Sapria (and presumably the rest of the family Rafflesiaceae) has not only lost just about all of its physical structure, but half of its genome -- including the entire array of genes that produce chloroplasts.  Stranger still, in the process it has picked up genetic material from its host, something called horizontal transfer.

So this puts paid to the incorrect notion a lot of people have that evolution always makes things bigger, stronger, smarter, and more complex.  Evolution is the law of whatever works at the time, and if what works is to jettison half the DNA along with chloroplasts, leaves, and true roots, that can happen.  And if you think about it, it makes sense; if you're a plant that spends nearly its entire life underground, why waste resources making structures like leaves and chloroplasts, not to mention all the proteins and pigments that go into making them work?  The oddest thing about the genetics, though, is that a lot of the genes that Sapria has picked up from its hosts don't seem to do anything; they appear to be "non-coding regions" of DNA that don't have any obvious function.  "There's something weird and different going on in this species," said Tim Sackton of Harvard University, who co-authored the paper, in an interview with Science News.  "Maybe these organisms that stretch the boundaries of existence tell us something about how far the rules can be bent before they can be broken."

Rafflesia and its relatives are certainly some of the strangest members of the plant kingdom, so much so that you have to wonder what other peculiarities are going to be uncovered by further analysis.  I just hope we don't find out that it eats rocket fuel and creates evil duplicates of people, because Judy Robinson barely escaped with her life, and that is not okay.

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Science writer Elizabeth Kolbert established her reputation as a cutting-edge observer of the human global impact in her wonderful book The Sixth Extinction (which was a Skeptophilia Book of the Week a while back).  This week's book recommendation is her latest, which looks forward to where humanity might be going.

Under a White Sky: The Nature of the Future is an analysis of what Kolbert calls "our ten-thousand-year-long exercise in defying nature," something that immediately made me think of another book I've recommended -- the amazing The Control of Nature by John McPhee, the message of which was generally "when humans pit themselves against nature, nature always wins."  Kolbert takes a more nuanced view, and considers some of the efforts scientists are making to reverse the damage we've done, from conservation of severely endangered species to dealing with anthropogenic climate change.

It's a book that's always engaging and occasionally alarming, but overall, deeply optimistic about humanity's potential for making good choices.  Whether we turn that potential into reality is largely a function of educating ourselves regarding the precarious position into which we've placed ourselves -- and Kolbert's latest book is an excellent place to start.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

The flora of prehistory

I grew up around plants.  Well, everyone does, more or less, but my parents were dedicated gardeners and naturalists.  My dad grew show-quality tea roses and taught me how to recognize the trees of my native Louisiana from the shapes of the leaves and texture of the bark when I was still in elementary school.  My mom's flower gardens more than once had people pulling over to take photographs.

Regular readers of Skeptophilia are well aware of my fascination with prehistoric animals -- like many kids I grew up with books on dinosaurs (and posters of dinosaurs and models of dinosaurs...).  So it shouldn't have been a surprise that I was thrilled when I found out that just like the animals of prehistory, the plants of prehistory were different than the ones we have today.  But I recall that my interest was mixed with shock -- if I went back to the Cretaceous Period, not only would there be T. rexes and triceratopses stomping about, but the plants through which they'd have been stomping wouldn't have been the familiar oaks and ashes and hollies and camellias that were so familiar, but an entirely different flora in which I doubt there'd have been a single species I could have identified.

Well, maybe a couple, if not to species, at least to family.  Some of the earliest flowering plants were magnolias, and from the fossilized flowers, they look pretty much like... magnolias.  Ferns have been around for a long, long time (far predating the dinosaurs, in fact), and conifers like the common pines, cedars, and cypresses I saw every day were plentiful all the way back in the Triassic Period, 240-odd million years ago.  

But that's about it.  And although some of the groups were there, the species themselves would have been different ones than what we see around us today.  Imagine it: forests of plants with huge and wonderful biodiversity, in which you wouldn't recognize a single one that's familiar.

The reason I'm thinking about all this floral prehistory is a link to some cool research that showed up last week in Geology that a friend and frequent contributor to Skeptophilia sent me, about a discovery of a phenomenally well-preserved flower in hundred-million-year-old amber from Myanmar.  

Valviloculus pleristaminis, flower in lateral view.  Image credit: Poinar, Jr. et al., doi: 10.17348/jbrit.v14.i2.1014.

Dubbed Valviloculus pleristaminis (the genus name comes from the Latin valva -- "a folding door" -- and loculus -- "compartment;" the species name means "lots of stamens"), the little flower is only distantly related to any extant species.  Botanists think that Valviloculus might be allied to one of two rather obscure families of plants native to the Southern Hemisphere -- Monamiaceae and Atherospermataceae -- but that's only a preliminary analysis.

Atherosperma moschatum, an Australian species that may be one of the closest living cousins to Valviloculus [Image is in the Public Domain courtesy of photographer Peter Woodard]

"This isn't quite a Christmas flower but it is a beauty, especially considering it was part of a forest that existed 100 million years ago," said emeritus professor George Poinar, Jr., of Oregon State University, who led the research into the newly-discovered species.  "The male flower is tiny, about two millimeters across, but it has some fifty stamens arranged like a spiral, with anthers pointing toward the sky.  Despite being so small, the detail still remaining is amazing.  Our specimen was probably part of a cluster on the plant that contained many similar flowers, some possibly female."

What's even more mind-blowing is something I've pointed out before; given how difficult it is to form a good fossil and then have it survive intact for millions of years, the species we know about (both animal and plant) probably represent about 1% of what was actually alive back then.  The vast majority of species came and went, leaving no traces.  So if we were to travel back to the mid-Cretaceous, when Valviloculus was living and flowering in the prehistoric forests, not only would we see it, but literally hundreds of other long-gone species as varied, attractive, weird, and fascinating as the ones we have today.

Imagine the colors, shapes, and scents, plants from tiny sprigs all the way to towering trees, and none of which we still have with us now.  Truly, in Darwin's words, evolution produced -- and continues to produce -- "endless forms most beautiful and most wonderful."

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This week's Skeptophilia book recommendation is apt given our recent focus on all things astronomical: Edward Brooke-Hitching's amazing The Sky Atlas.

This lovely book describes our history of trying to map out the heavens, from the earliest Chinese, Babylonian, and Native American drawings of planetary positions, constellations, and eclipses, to the modern mapping techniques that pinpoint the location of stars far too faint to see with the naked eye -- and objects that can't be seen directly at all, such as intergalactic dust clouds and black holes.  I've always loved maps, and this book combines that with my passion for astronomy into one brilliant volume.

It's also full of gorgeous illustrations showing not only the maps themselves but the astronomers who made them.  If you love looking up at the sky, or love maps, or both -- this one should be on your list for sure.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

How plants see the world

The final project in my AP Biology class was to design a piece of original research, carry out an experiment, and report on the results.  I was amazed at the creative ideas students came up with, and the elegance of their methods for finding an answer -- methods that were limited by considerations of budget, space, and time.

One of the best ones I recall came out of a discussion in class when we were studying botany.  I was telling the students about statoliths, small, dense particles in the cells of plants near the tips of roots and stems, that sink to the bottom of the cell and tell the plant what direction is up.  This detection of the pull of gravity allows for gravitropism, in which the roots grow downward and the stems upward, even in the absence of light.

This sense gets taken away in zero-g conditions, as on the International Space Station.  Experiments there have shown that without an apparent pull of gravity, seeds will sprout and the roots and stems grow in whatever direction the seed is oriented -- even if that means the roots will grow upward and the stems downward.

A student asked, "What would happen if you increased the pull of gravity?  In a spaceship floating in the atmosphere of Jupiter, for example?"

I had no idea, and I told him so.  Good question, but to my knowledge it hadn't ever been tested.

So when the end of the year came, that student decided to find out.

Since a trip to Jupiter was kind of out of the question, he designed an apparatus to simulate higher-gravity conditions.  He got an old ceiling fan motor and some lengths of PVC pipe, and built himself an electronic whirligig.  He then grew sunflower seeds in two-liter soda bottles hanging on the ends of the vanes -- attached the bottles and then spun the hell out of them.  Knowing the rotational speed of the whirligig and the radius of the vanes, he could calculate the centripetal force being exerted on the bottles, and thus the increase in apparent gravitational pull.

And when he opened up the bottles, he found something extraordinary.  The higher the average gravitational pull the seedlings experienced, the shorter they were, and the thicker the stems.  Up to the limit of his whirligig's speed, it was a nearly linear relationship -- higher pull = shorter, stouter seedlings.

So somehow, plants can not only detect the direction of the pull of gravity, but its strength.

We're just starting to understand how plants sense the world, and what sorts of responses they are capable of.  A paper last week in Current Biology, describing research conducted at the University of Helsinki, unlocked a piece of what might have been going on with my student's spinning sunflowers.  The research team, led by botanist Juan Alonso-Serra, found that birch trees whose branches are weighted -- simulating a higher-mass crown -- increase the rate of the radial growth of their trunks in order to better support the higher weight.  Better still, they found that the gene called ELIMÄKI (EKI) is critical to this response; plants with a defective EKI locus were not able to do this growth-rate compensation, and eventually collapsed.

The authors write:

Our results highlight a regulatory circuit by which weight in tree trunks mechanically stimulates cambial growth.  The ELIMÄKI locus participates in this circuit, as shown by its requirement at various levels, from weight-induced growth response to the proper control of gene expression related to touch-induced mechanosensing.  The circuit facilitates the local acquisition of the biomechanical characteristics of xylem in the correct spatiotemporal manner, which systemically leads to a correct vertical proprioception response.  It remains to be studied how weight- and development-derived forces are sensed and transduced into radial growth, but our results indicate a critical role for a degree of lateral stem movement.  Similarly, it remains to be studied whether the ELIMÄKI locus contributes directly to the sensing of the proprioceptive signal or whether it is only part of its response.  Our results provide a mechanism through which the critical height:diameter ratio implied by the mechanical theory of tree evolution can be achieved.

Which is pretty amazing.  My long-ago student's research was prescient -- and now we have a possible genetic mechanism by which this response is modulated.  (Note, however, that Alonso-Serra's team still had no model for how plants are sensing the higher weight.)

Plants are aware of their surroundings in ways that are only now being understood.  One of the more mysterious responses, for which I have still heard no particularly convincing explanations, is crown shyness -- the tendency in some tree species to avoid coming near the branches of other trees, leaving "lanes" of open sky when viewed from below.

A grove of the Malaysian dipterocarp Dryobalanops aromatica, showing crown shyness [Image is in the Public Domain]

Why the usual approach -- growing taller and broader than your neighbor, so as to have better access to light (and as a side benefit, discouraging competition from the individuals around you) -- doesn't apply here, I don't know.  Two possible explanations are that having your branches not touch your neighbors' results in less chance of mechanical damage from the wind, and also provides less of a pathway for herbivores to get to you from nearby trees.

But it's hard for me to see how such minor benefits would result in such a striking response, which apparently has evolved more than once in only distantly-related species.

Also not fully understood is the phenomenon of photoperiodism, the way many plants time when to flower based on the relative lengths of the day and night.  There are a few suggestive experiments that the critical thing is the length of the night rather than the day -- breaking up the dark period by even a short flash of light disrupts the response, whereas a short dark period in the middle of the day has no effect.  Light in the red region of the spectrum has the strongest ability to disrupt this response, probably because a protein involved in the response (phytochrome) has its highest sensitivity to red light.  Some plants are extraordinarily sensitive, responding to changes in the day/night length of only a few minutes.

But exactly how they're accomplishing all of this is only partially understood.

So if we're just beginning to figure out how our own senses work, we've barely scratched the surface with the sensory apparatus of plants.  What's certain is they're not the mostly-inert little lumps we once thought, passively absorbing sunlight, otherwise unaware of their surroundings.  Plants are capable of sophisticated sensing and response -- whether to day/night length, the proximity of neighbors, weights on the branches -- or being spun around in a cobbled-together electric whirligig.

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This week's Skeptophilia book of the week is both intriguing and sobering: Eric Cline's 1177 B.C.: The Year Civilization Collapsed.

The year in the title is the peak of a period of instability and warfare that effectively ended the Bronze Age.  In the end, eight of the major civilizations that had pretty much run Eastern Europe, North Africa, and the Middle East -- the Canaanites, Cypriots, Assyrians, Egyptians, Babylonians, Minoans, Myceneans, and Hittites -- all collapsed more or less simultaneously.

Cline attributes this to a perfect storm of bad conditions, including famine, drought, plague, conflict within the ruling clans and between nations and their neighbors, and a determination by the people in charge to keep doing things the way they'd always done them despite the changing circumstances.  The result: a period of chaos and strife that destroyed all eight civilizations.  The survivors, in the decades following, rebuilt new nation-states from the ruins of the previous ones, but the old order was gone forever.

It's impossible not to compare the events Cline describes with what is going on in the modern world -- making me think more than once while reading this book that it was half history, half cautionary tale.  There is no reason to believe that sort of collapse couldn't happen again.

After all, the ruling class of all eight ancient civilizations also thought they were invulnerable.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]