What’s in a Name?

Part One: Common vs. Scientific Names

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img_3146-staghornsumac

When I was a kid growing up on a farm in southwestern Ontario, sumac seemed to be everywhere, with its long, spindly stems, big, spreading compound leaves, and fuzzy red berries. I always found the plant beautiful, and had heard that First Nations people used the berries in a refreshing drink that tastes like lemonade (which is true… here’s a simple recipe). But often, we kids were warned by adults that this was “poison sumac,” not to be touched because it would give us itchy, burning rashes, like poison ivy did. In fact, plenty of people would cut down any nascent stands to prevent this menace from spreading. We were taught to fear the stuff.

 

Toxicodendron_vernix#1978a#2_400
THIS is the stuff you need to look out for. Via The Digital Atlas of the Virginia Flora

It was many years later before I learned that the red-berried sumacs I grew up with were not only harmless, but were also not closely related to the poisonous plant being referred to, which, as it turns out, has white berries and quite different leaves. Scientifically speaking, our innocent shrub is Rhus typhina, the staghorn sumac, while the rash-inducing plant is called Toxicodendron vernix. Not even in the same genus. Cautious parents were simply being confused by the similarity of the common names.

 

This story illustrates one of the ironies of common names for plants (and animals). Though they’re the way nearly everyone thinks of and discusses species, they’re without a doubt the most likely to confuse. Unlike scientific (Latin) names, which each describe a single species and are, for the most part, unchanging, a single common name can describe more than one species, can fall in and out of use over time, and may only be used locally. Also important to note is that Latin names are based on the taxonomy, or relatedness, of the species, while common names are usually based on either appearance, usage, or history.

 

This isn’t to say that common names aren’t valuable. Because common names describe what a plant looks like or how it is used, they can convey pertinent information. The common names of plants are also sometimes an important link to the culture that originally discovered and used the species, as in North America, where native plants all have names in the local languages of First Nations people. It seems to me, although I have no hard evidence to back it up, that these original names are now more often being used to form the Latin name of newly described species, giving a nod to the people who named it first, or from whose territory it came.

 

One high profile case of this in the animal world is Tiktaalik roseae, an extinct creature which is thought to be a transitional form (“missing link”) between fish and tetrapods. The fossil was discovered on Ellesmere Island in the Canadian territory of Nunavut, and the local Inuktitut word “tiktaalik”, which refers to a type of fish, was chosen to honour its origin.

 

But back to plants… Unlike staghorn sumac and poison sumac, which are at least in the same family of plants (albeit not closely related within that family), sometimes very distinct species of plants can end up with the same common name through various quirks of history. Take black pepper and bell or chili peppers. Black pepper comes from the genus Piper, and is native to India, while hot and sweet peppers are part of the genus Capsicum. Botanically, the two are quite distantly related. So why do they have the same name? Black pepper, which bore the name first, has been in use since ancient times and was once very highly valued. The confusion came about, it would seem, when Columbus visited the New World and, finding a fruit which could be dried, crushed, and added to food to give it a sharp spiciness, referred to it as “pepper” as well.

Sa-pepper
A black peppercorn. Easy to confuse with a chili pepper, I guess? Via: Wikimedia Commons

 

Another interesting, historically-based case is that of corn and maize. In English-speaking North America, corn refers to a single plant, Zea mays. In Britain and some other parts of the Commonwealth, however, “corn” is used to indicate whatever grain is primarily eaten in a given locale. Thus, Zea mays was referred to as “Indian corn” because it was consumed by native North Americans. Over time, this got shortened to just “corn”, and became synonymous with only one species. Outside of Canada and the United States, the plant is referred to as maize, which is based on the original indigenous word for the plant. In fact, in scientific circles, the plant tends to be called maize even here in North America, to be more exact and avoid confusion.

 

1024px-Spanish_moss_at_the_Mcbryde_Garden_in_hawaii
Not Spanish, not a moss. Via: Wikimedia Commons

And finally, for complete misinformation caused by a common name, you can’t beat Spanish moss. That wonderful gothic stuff you see draped over trees in the American South? That is neither Spanish, nor a moss. It is Tillandsia usneoides, a member of the Bromeliaceae, or pineapple family, and is native only to the New World.

 

And that wraps up my very brief roundup of confusing common names and why they should be approached with caution. In part two, I’ll discuss Latin names, how they work, and why they aren’t always stable and unchanging, either.

 

There are SO many more interesting and baffling common names out there. If you know of a good one, let me know in the comments!

 

*Header image via the University of Guelph Arboretum

Charity Among Vampires

(Via: National Geographic)

Common Name: The Vampire Bat

A.K.A.: Subfamily Desmodontinae

Vital Stats:

  • Subfamily contains three species; the common vampire bat (Desmodus rotundus), the hairy-legged vampire bat (Diphylla ecaudata), and the white-winged vampire bat (Diaemus youngi)
  • All three feed only on blood, a phenomenon known as hematophagy
  • The common vampire bat feeds primarily on mammals, while the other two species prefer avian blood
  • Can live up to 20 years in captivity

Found: Throughout Mexico, Central America, and all but the most southern reaches of South America

It Does What?!

Several years ago while on a botanical expedition in the rainforests of South America, I woke one morning to find that one of the other team members, still fast asleep in his hammock, had – apparently – been stabbed in the shoulder during the night. A surprising amount of blood had run down his arm, and yet he snored peacefully away. What the hell had happened to this guy, and was he the world’s deepest sleeper, or what?

Nope. Turns out he had just unwittingly provided a good meal for Desmodus rotundus… the common vampire bat.

As horrifying as it may seem to have flying vermin drinking your blood whilst you sleep, it’s really not as bad as pop culture would have us believe. The bats are more scavenger than predator. To begin with, they prefer stealth and guile to any kind of open attack. Sleeping animals are best, and victims are never approached from the air, Caped Crusader-style. Instead, the bat will land nearby and walk on all-fours over to its prey. From there, it uses heat sensors in its nose (similar to some snakes) to detect where blood vessels pass close to the surface of the skin. In cows, another favourite blood donor of Desmodus, bites are usually just above the hooves or around the ears.

Breakfast of Champions
(Via: National Geographic)

Also contrary to popular belief, the bites are never violent; they’re more like a tiny nick from a very sharp razor- painless, but they tend to bleed a lot. In this case, they’re bleeding a lot because the bat’s saliva contains anticoagulents, preventing the blood from clotting. The bat will lap at the cut with its tongue (no blood-sucking here), transferring saliva into the wound, which will sometimes continue to bleed for hours afterward.

An entire feeding session takes the bat only about 20 minutes, during which time it can consume up to half its own weight in blood. How is this possible? Vampire bats have an amazingly efficient excretory system; the plasma (liquid) portion of the blood is immediately absorbed and passed through the kidneys. Within minutes of beginning to feed, the vampire starts to pee at the same time, and continues to do so until its meal has been reduced to a manageable volume. (Did they leave this part out of the Twilight movies?)

Creepy as these little beasts may seem, they have a surprisingly enlightened social structure. Vampire bats have been cited by animal behaviourists as one of the few examples of reciprocal altruism (“tit for tat”) in nature. You see, the vampire lifestyle is a bit precarious- a bat will die if it fails to feed for two successive nights. As a lifesaving measure, a bat in such dire straits will actually beg another bat for food. The other bat will then regurgitate some of its meal – just enough to make do – into its hungry neighbour’s mouth. Impressively, the bats even keep score. A hungry animal will turn preferentially to a bat it has helped out in the past, and cheaters are recognised and allowed to starve.

“Okay, what do we learn to imitate next?”
(Via: conservationcentre.org)

Far from being mindless, aggressive little monsters, vampire bats are altruistic, intelligent creatures. How intelligent? Researchers who housed a vampire bat with a hen observed the bat to mimic the behaviour of a chick so effectively that the hen settled down on top of the bat as she would to keep a baby warm. The bat then nicked her on the stomach and drank her blood while she tried to mother it.

Now that’s just creepy.

[Fun Fact: Vampire bats listen to the rhythm of an animal’s breathing to determine whether or not it’s asleep. They prefer to return to a victim they’ve had previous success with, and evidence suggests that they can identify individual humans by their breathing noises in the same way that we recognise individuals by their voices.]

[Also: The common vampire bat can jump up to three feet off the ground to reach large prey.]

Says Who?

  • Groger & Wiegrebe (2006) BMC Biology 4:18
  • Lee et al. (2012) PloS ONE 7(8): e42466
  • Schutt (2008) Natural History, November Issue, pg.22
Become a donor today!
(Via: Vampire Legends)

Nights of the Living Dead… Further Horrors of the Insect World

(By: Paul Nylander Via: The Tucson Citizen)

Common Name: The Tarantula Hawk

A.K.A.: Genera Pepsis and Hemipepsis

Vital Stats:

  • The two genera make up Tribe Pepsini in Family Pompilidae
  • Grow up to 5cm (2”) long
  • Stingers are up to 7mm (1/3”) long
  • Quite long lived for wasps, with lifespans of more than a year
  • Adults feed primarily on milkweed nectar

Found: Across much of the tropics and southern hemisphere

It Does What?!

Happy Halloween, readers! Today’s the day when we’re surrounded by images of zombies, witches, ghosts, and spiders- all creatures meant to scare us on some level. Of course, only one of these things is real. And spiders truly are a scary thing for many people. For all you arachnophobes out there who are feeling vaguely uncomfortable about the preponderance of fake spiders out there today, did you ever wonder what the spiders fear? What keeps tarantulas, the biggest, scariest arachnids of them all, awake at night? Tarantula hawks, that’s what. If spiders had Halloween, this is what they would dress up as.

A creature that can kill small rodents being outmatched by a nectar-sipping insect. Sad.
(Via: Wikimedia Commons)

Like any good mother, the female tarantula hawk wants to ensure that her baby has all the food it requires to grow up into a healthy adult wasp. Rather than bag a large piece of prey and have it spoil by the time her egg hatches, she has developed an ingenious system of keeping meat fresh.

Spying a tarantula from the air, she will attack, injecting the spider with her venom as it struggles to bite her. A particularly hard and slippery exoskeleton renders this counterattack ineffective; the fangs simply slip off her. Before long, the tarantula has succumbed to her venom and is alive, but completely paralysed. Once the prey has been neutralised, she sets out over land, dragging the spider up to 100m (quite a long way, considering the scale involved) back to the site of a burrow she has dug out. Here, our mom-to-be lays a single egg on the helpless spider’s abdomen, then proceeds to immure it in the burrow.

A hundred metres starts to look like a very long trip.
(By: Erin Zimmerman, taken during my field work in Guyana)

But this is only the beginning of the horror for the paralysed spider. Soon after, the egg hatches, and the hungry larva tunnels directly into the spider’s flesh, eating as it goes. The larva instinctively knows to avoid the tarantula’s vital organs as it eats, thereby keeping the prey alive for as long as possible. After several weeks of chowing down, the larva finishes off the job and emerges from the spider’s body, having now matured into a wasp. It then simply unseals the burrow and flies away, leaving the late tarantula in its ready-made grave.

Wondering what happens when a person gets stung by one of these? It’s an interesting question, because the answer is both “a lot” and “not much”. You see, the paralytic agent in the venom only works on invertebrates, and won’t actually do any real damage to human tissue. Before you go trying to catch one, though, know that, in terms of immediate reaction, tarantula hawks are considered to have the single most painful insect sting in the world. It’s best described by an entomologist who has actually experienced such a sting:

“Advice I have given in speaking engagements was to ‘lay down and scream’. The reasoning being that the pain is so debilitating and excruciating that the victim is at risk of further injury by tripping in a hole or over an object in the path and falling onto a cactus or into a barbed wire fence. Such is the pain, that few, if any, can maintain normal coordination or cognitive control to prevent accidental injury. Screaming is a satisfying expression that helps reduce attention to the pain of the sting itself.” [Schmidt 2004]

In short… don’t touch these.

A few words now on just how frighteningly well-adapted this wasp is. Not only is it covered in armour and full of incredibly painful venom, but at roughly the size of your little finger, it’s one of the largest wasps out there, and more of a fight than most insectivores want to deal with. It is essentially without predators. And lest any potential enemies forget why they’re not touching it, the tarantula hawk has both a distinct colour and a characteristic odour, meant to remind aggressors of the pain associated with any previous run-ins. Researchers have described tarantula hawks as being “among the best defended animals on earth” [Schmidt 2004]. And because success always spawns imitation, there are now several other creatures mimicking the appearance of the female tarantula hawk as a form of protection, including the more-or-less defenceless males of the same species.

So the next time you shudder at the thought of a tarantula stalking you in the wild, stop and remember what might be stalking it.

[Fun Fact: Despite its phenomenal pain-inducing qualities, tarantula hawk venom is only about 5% as lethal as honeybee venom, based on studies by people who inject white mice with horrible things for a living.]

Says Who?

  • Alcock & Kemp (2006) Ethology 112: 691-698
  • Kurczewski (2010) Northeastern Naturalist 17(1): 115-124
  • Schmidt (2004) Journal of the Kansas Entomological Society 77(4): 402-413
  • Schoeters et al. (1997) Canadian Journal of Zoology 75: 1014-1019

Ergot: Bringing the Crazy Since 800 A.D.

(Via: The University of Illinois Extension Collection)

Common Name: Ergot, Ergot of Rye

A.K.A.: Claviceps purpurea (and other Claviceps species)

Vital Stats:

  • Around 30-40 species in genus Claviceps, all parasites of various types of grasses
  • Parasitizes rye, barley, and wheat crops in temperate regions
  • Problematic in Africa due to its parasitism of sorghum and millet

Found: Throughout temperate and tropical regions, though historically most problematic in Europe, Africa, and North America

It Does What?!

Disrupts human history and generally scares the hell out of people, to put it mildly. But before we get into that, let’s start with what this stuff is. An ergot infection begins when a microscopic fungal spore lands on the open floret of a grass plant. In northern agricultural areas, rye and, to a lesser extent, barley are particularly susceptible to these spores. Once on the receptive flower, the spore behaves as though it were a pollen grain, growing down the style until it reaches the ovary. At this point, it destroys the ovary and links into the adjoining vascular tissue, where it can parasitize the plant for nutrients.

With plenty of food on tap, the fungus grows into the space that the grain would have otherwise filled. Early on, it forms into a soft, white mass that causes a sugary liquid to drip from the flower. This liquid is filled with spores and is spread to other plants by hungry insects as they fly from flower to flower. Later in the growing season, around the time neighbouring non-parasitized grains are ripening, the fungal mass dries and hardens into a sclerotium (a sort of fungal seed body) that looks a bit like wild rice, and drops to the ground. This sclerotium will sit dormant on the ground until spring, when moisture will cause it to sprout small mushrooms, which produce spores for the new season.

Hint: Wild rice doesn’t do this when you get it wet.
(Via: mycotopia.net)

Still reading? Good. Here’s the interesting part. Let’s say you’re a farmer in the Middles Ages, and the infected plants in question are in your field. Before the ergot sclerotia drop to the ground, they get harvested with the rest of the crop, and end up getting made into bread for you and your family. Well, it turns out those sclerotia are full of a toxic alkaloid called ergotamine, and after eating enough loaves of bread to build the compound up in your systems, you and your nearest and dearest have contracted ergotism. Fed some of that rye to your cows? Now they’ve got it, too!

Ergotism delivers a one-two punch of physical and psychological symptoms. Physically, the alkaloid constricts blood vessels, leading to an intense burning sensation in the arms and legs which can eventually cause gangrene and loss of the entire limb. Some sufferers also develop a persistent ringing in the ears. That’s before the seizures and untimely death set in. Psychologically… well, it makes you crazy. As in, hallucinations and irrational behaviour, which lead many victims to be ostracised by their communities. Ergotism is speculated to have been the cause of the Dancing Mania (not as fun as it sounds) that hit Europe in the Middle Ages. Huge numbers of people were struck by an uncontrollable urge to dance – violently and while screaming – until they collapsed from exhaustion. Did I mention that this stuff is where LSD came from? The drug was originally synthesised from ergotamine, handily delivering all the craziness with none of the gangrenous limb loss.

Nope, nothing suspicious-looking here.
(Via: Wikimedia Commons)

The cure for all this horror? Well, if you got to it early enough, simply not eating any more contaminated grain would cause symptoms to slowly abate. Unfortunately for medieval peasants, who ate a lot of rye and suffered most of history’s outbreaks, the cause of the disease was completely unknown. Weird-looking sclerotia were so common that they were thought to be a natural feature of rye. That old standby, “It’s the wrath of God” actually seemed supported, since sufferers who left the affected area on pilgrimages immediately began to show improvement (hence another term for the disease, ‘Holy Fire’). Sadly, it took the better part of a millennium before someone worked out what was really going on, and major outbreaks occurred right up to the 19th century. Even in the 21st century, minor outbreaks have occurred in developing countries, such as the case in Ethiopia in 2001, caused by infected barley.

Speaking of disrupting human history, some researchers have speculated that an ergotism outbreak caused the strange behaviour that resulted in the Salem witch trials of the late 17th century. Others have disputed this claim, noting, among other points, that ergotism was known and recognisable by this point in history. We may never know for sure.

[For other historical events in which ergotism may have played a role, check out the first reference below.]

[Fun Fact: Due to its action as a vasoconstrictor, ergotamine is now used, in purified form, to treat migraines and post-natal bleeding.]

Says Who?

Randomly Assembled and Surprisingly Dangerous: The Platypus

(Via: National Geographic)

Common Name: The Duck-Billed Platypus

A.K.A.: Ornithorhynchus anatinus

Vital Stats:

  • Only species of Family Ornithorhynchidae
  • Males average 50cm (20”) long, females 43cm (17”)
  • Weigh between 0.7 and 2.4kg (1.5 – 5.3lbs.)
  • Body temperature of 32 degrees Celcius; five degrees lower than placental mammals
  • Live up to 17 years in captivity
  • Eat freshwater crustaceans, worms, and insect larvae

Found: Eastern Australia and Tasmania

It Does What?!

Besides looking like it was assembled from spare parts? We’ve all seen pictures of platypuses (yes, “platypuses”, not “platypi”) before, and everyone knows what total oddities they are: the duck-like bill, the beaver-esque tail, the fact that they lay eggs, despite being mammals; but behind these weird traits lie… even more weird traits! So let’s take a moment to appreciate the lesser-known eccentricities of the platypus, shall we?

First off, these cuddly looking freaks are actually dangerous. Male platypuses have a spur on each hind foot which is filled with a venom powerful enough to kill a large dog. While it isn’t enough to take out a human, it does cause severe, incapacitating pain whose after-effects can last for months. One of only a very few venomous mammals, the male’s venom production increases during the breeding season, suggesting its purpose may lie in competition with other males.

Why your dog and your platypus shouldn’t play together.
(By Jason Edwards, via: How Stuff Works)

And speaking of breeding, reproduction in platypuses isn’t exactly ‘mammal standard’, either. Unlike all other mammals, which have two sex chromosomes (X and Y; XX for females, XY for males, with rare exceptions), the platypus has ten. Talk about evolutionary overkill. A male platypus has the pattern XYXYXYXYXY, while a female has ten Xs. Researchers have found that the actual genetic structure of these sex chromosomes is actually more similar to birds than mammals, although 80% of platypus genes are common to other mammals.

After this alphabet soup of chromosomes arranges itself, up to three fertilised eggs mature in utero for about four weeks; much longer than in most other egg-laying species (in birds, this may be only a day or two). Once laid, the eggs are only about the size of a thumbnail, and hatch in around ten days. While platypuses produce milk, they don’t actually have proper teats to suckle their babies- the fluid is released from pores in the skin. A small channel on the mother’s abdomen collects the milk, which is then lapped up by the young. Strangely, the babies are actually born with teeth, but lose them before adulthood. Such is the impracticality of platypus design…

Adorably impractical.
(Via: noahbrier.com)

Finally, let’s explore platypus hunting methods. Platypuses are the only mammals with the sixth sense of electroreception. Those leathery duck bills of theirs are actually precision receptors that can detect the electric fields created in the water by the contractions of muscles in their prey. Considering the prey in question is largely worms and insect larvae, we’re talking big-time sensitivity here. The bill is also very receptive to changes in pressure, so a movement in still water can be picked up in this way as well. Researchers have suggested that by interpreting the difference in arrival time of the pressure and electrical signals, the hunter may even be able to determine the distance of the prey. This would be especially useful, given that platypuses close both their eyes and ears when hunting. In fact, they won’t even eat underwater; captured food is stored in cheek pouches and brought to land to be consumed.

So there you have it. The platypus: even weirder than you thought.

[Fun Fact:The female platypus has two ovaries, but only the left one works.]

Intelligent Design’s Worst Nightmare
(Via: Animal Planet)

Says Who?

  • Brown (2008) Nature 453: 138-139
  • Grant & Fanning (2007) Platypus. CSIRO Publishing.
  • Graves (2008) Annual Review of Genetics 42: 565-586
  • Moyal (2002) Platypus: The Extraordinary Story of How a Curious Creature Baffled the World. Smithsonian Press.

The Stinging Tree, or, Australia Hates Mammals

Can’t Touch This
(via: anhs.com.au)

Common Name: Stinging Tree, Gympie-Gympie

A.K.A.: Dendrocnide moroides

Found: Rainforests of Northeastern Australia

It Does What?!

Australia, which was apparently intended only for the very bravest of human beings, is home to many of the world’s most poisonous snakes, spiders, and scorpions. Even the surrounding ocean is exceptional for the number of ridiculously venomous species it contains. Still, a person could be forgiven for thinking that, so long as they stay out of the water and keep away from the creepy-crawlies, they’ll be okay. Ha ha ha… nope. In Australia, everything is out to get you.

Meet Gympie-Gympie, the Stinging Tree (or to be more accurate, stinging shrub). Growing in rainforest clearings and along creek edges- anywhere the canopy is broken- this two metre (6.5ft) high plant has large, heart-shaped leaves and juicy purple fruit. And every square centimetre of it, from the soil on up, is covered in tiny, poison-filled hypodermic needles. These hollow silicon needles are delicate enough to break off at the slightest touch, leaving them embedded in the skin of whatever creature was unfortunate enough to do so. The skin will often then close over them, making the needles nearly impossible to remove. The substance they’re filled with is a very potent neurotoxin with a very long shelf life- herbarium specimens of the plant collected in 1910 are still able to cause pain. And since the body is unable to break down silicon, this all adds up to a very long punishment for a very small mistake.

Go on, I dare you.
(Photo by Melanie Cook)

A brief brush against a stinging tree produces intense pain that peaks after about half an hour, but can literally take years to subside completely. Numerous dogs and horses have died because the pain was so intense. There is even one official record of a human having died- a Dutch botanist of the 1920s. Oddly enough, no actual tissue damage is done by the neurotoxin- death due to the plant is attributed to heart failure due to the shock of the pain, described by one researcher, Dr. Marina Hurley, as “like being burnt with hot acid and electrocuted at the same time.” An ex-serviceman who fell right into one of the trees while crossing a creek in the 1940s describes having had to be tied down to his hospital bed for three weeks because the discomfort was so intense. One intrepid/insane researcher actually purified the neurotoxin and injected himself with it, suffering terribly and thereby proving that the toxin, rather than the needles, causes the majority of the pain. But not all of it… simply standing near a gympie-gympie for an extended period can cause allergic reactions and nosebleeds as the needles are shed in the wind.

“I eat neurotoxins for breakfast.”
(Via: Billabong Sanctuary)

So this must be just about the best herbivore-defence system ever, right? Amusingly, no. The trees still undergo heavy damage due to hungry spiders, ants, snails, and especially beetles, all of which can avoid its defences. The tree is even prey to one species of marsupial, the red-legged pademelon, which is either immune to the neurotoxin or has enormous pain tolerance. So why develop this extensive arsenal if it’s completely ineffective? One expert has suggested that it may have evolved to protect the plants from the now long-extinct giant Diprotodonts which once inhabited the Australian rainforest, making it one more dangerous relic of a long-ended war. You win, stinging tree, you win.

[Fun Fact: The best way to attempt to remove some of those poisonous silicon needles embedded in your arm?  Wax hair removal strips, according to the Queensland ambulance service.]

Says Who?