So, taxonomy… That’s where you stuff dead animals, right?

I have a confession to make. If you ask me these sorts of questions:

Should I plant my beans when the Moon is waning?

Why are my Fuchsias going mouldy?

Why are snails attacking my prize cabbages like tiny, hungry, Genghis Khans?

I’m afraid I would have NOT A CLUE how to answer you. Because my shameful secret is that I know very, very little about actually keeping plants alive. I mean, maybe a tiny little bit more than your average person on the street, as if you hang around avid gardeners like my Nan or botanic gardens you tend to pick stuff up, but generally speaking I won’t even begin to know how to give you an answer.

However, if you ask me about, say, photosynthesis, evolution, family names or morphology, I would probably at least be able to summon some sort of response. This is because although I work with plants, I am not a gardener. Asking me about gardening is only a little bit less weird than asking your GP about how to look after your pet cat because, hey, cats and humans are both mammals, so your GP must know all about cats!

So anyway, to clear this up, I thought I’d do a brief run-down of some of the sorts of people who work with plants, what they do and why.

A short, non-exhaustive-by-any-means list:

Gardeners

Plant scientists/geneticists/biochemists etc

Horticulturalists

Botanists

Ecologists

Tree surgeons

Plant breeders

Taxonomists (note: different from taxidermists)

So what do all these people do? Well, let’s take one plant.

Photograph by Adele Julier

Here’s a plant. It is called Rothmannia longiflora, if anyone was interested. It’s in the Rubiaceae. For the sake of argument, it could be the plant we’re talking about here but really it’s just a pretty picture to go along with this post because PLANTS ARE PRETTY. LOOK, A PRETTY FLOWER.

A botanist might ask what the plant’s name is, what is the arrangement of its leaves, which family is it in? A taxonomist might be more concerned with who named it, which species it is most closely related to and whether it can really be considered a separate species from this other plant (although botanists and plant taxonomists tend to overlap quite a lot in their interests). A horticulturalist might be concerned with how to optimise the conditions for germination of the plant’s seeds. A plant breeder might be interested in novel characteristics of the plant’s flowers so they could cross it with other species to produce marketable varieties. A plant scientist might wonder which genes control its floral morphology or whether or not it exhibits CAM photosynthesis. An ecologist might try to figure out how that plant lives in its environment and why, maybe how endangered it is too.

Basically, we’re a bunch of people who work on different aspects of a hugely diverse Kingdom of organisms and who specialise in different areas and aspects of that Kingdom. The result of this is that, even though they’re both ‘plant people’, if you asked a plant geneticist why your apple trees were looking peaky, you’d likely get about as much sense as if you asked a tree surgeon about the role of COP10 in determining stomatal distribution in Arabidopsis thaliana. Not to say that there aren’t tree surgeons who know about genetics or geneticists who have secret green fingers, but purely by dint of their jobs, they’d have no reason to know those things.

Obviously there are many more ways people work with plants, and a lot of overlap in what we do, but I hope this maybe helps clarify some differences between your various plant-loving professionals.

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What’stomata with you?

Tiny little mouths. Swarms of them on every leaf, gaping wide open or clamping shut in order to keep their plants alive. They’re called stomata and help prevent plants from losing so much water that they dehydrate whilst allowing enough carbon dioxide into leaves that they can continue the amazing job of making their own food from what is essentially fresh air, water and sunshine. They allow plants to live on land and do things like survive droughts or forgetful gardeners and could play a big part in aiding adaptation to climate change, making them topical and important.

So, what actually are these mysterious structures? They’re basically pores on the surface of plants that let air in and out. One stoma comprises of two guard cells which control how open the pore is, an air cavity underneath that and, sometimes, a whole lovely bunch of other cells and maybe even other stomata. The science behind what controls their closing and opening is really quite complicated but what it boils down to essentially, is that when there’s more water about they open and when there’s less, they close. This is helped by their guard cell wall properties (see caption below).

As a picture is worth a thousand words (most of them about my mental age) here’s one which might make things a little clearer:

They're my SEM images and I can do what I like to them, thanks very much.

The ‘lips’ of these happy little fellas are their guard cells’ thick inner walls, allowing them to flex open when they contain more water and close when flaccid. Oh, and they’re quite small- the scale bar= 50um. That’s 0.05mm or less than a tenth of a millimetre.

This picture also illustrates why I’m rambling about these cute little things. My MSc research project is focussed on better understanding how stomata develop in Begonia and so, for the next 2-3 months I’ll be eating, breathing and living stomata science.

As part of this I get to work with some very exciting bits of kit like a scanning electron microscope, with which I took the picture above. Preparing the samples for SEM is almost as fun as photo shopping googly eyes onto the resulting pictures, as it involves exposing your leaves to a horrifying amount of ethanol, marinating them in liquid CO2 and then coating them in platinum using a machine seemingly designed purely to mimic an alien abduction. You then load them onto a sample holder which bears more than a passing resemblance to the Starship Enterprise and BLAST THEM WITH ELECTRONS in a vacuum. Science is ridiculous when you stop to think about it.

I realise this post departs somewhat from the usual crazy plants theme of this blog, but as stomata are basically all I think about these days, it made sense somewhere in my SEM-mangled brain to write about them.

Disclaimer: Terrible Pun courtesy of my undergrad dissertation supervisor Howard, on Twitter @GriffithsHoward.

SEM image taken by yours truly on Kew’s glorious SEM.

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Giant hairy berries.

Sometimes, on my MSc course, I learnt things that really stuck with me. Things that once you know, you can’t un-know. One such thing is that oranges are full of hairs. The fruit type is called a ‘hesperidium’ and each little juicy bit in an orange is, in fact, a swollen-to-bursting-point trichome, or plant hair.

Botanically, oranges are actually a type of berry. That makes them giant berries filled with hair.

Enjoy your breakfast juice!

Apple is unimpressed by Orange's attempt at a pun and its fruit morphology.

Apple is unimpressed by Orange’s attempt at a pun and also its carpological morphology.

 

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Some families united purely by awesomeness (ok, and genetics).

Plants are a weird bunch. We’ve known this for a very long time but since genetics and all its assorted magic came into being, we’ve found out that they’re weirder than we ever even imagined. This post is about three families which no one would ever have thought were closely related but which genetics has proven to be part of the same order (a group of families all more closely related to each other than to anything else). They’re one big collection of oddballs, which is probably why I enjoy them so much.

Firstly, there’s the Platanaceae. You’ll probably know these guys as London Planes; the gnarly, unabashedly big, vividly green stalwarts of posh London avenues. I love these trees with their bauble-like inflorescences and tendency to destroy puny human inventions like pavements and roads with their mighty roots. Here’s one, entirely upstaging the church next to it.

By Lestat (Jan Mehlich) (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC-BY-SA-2.5 (http://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons

‘Does that pile of recycled dirt and sediment build itself out of thin air using nothing but flimsy green solar panels? I think not!’

Then there’s the Nelumbonaceae, or Lotuses. Their flowers are wonderful colours with a crazy gynoecium (female reproductive bit) that looks like it’s made of play dough with holes poked in it and their leaves are the most fun things to throw water on since the alkali metals. Here’s quite a nice video with a jolly soundtrack showing them being awesomely water repellent.

People are trying to use this property to make paints and other things that would usefully repel water. It’s pretty spectacular and there are some interesting physical properties behind it all. (Here’s a page with more information and links, for those of you who want to read about micro-topography and superhydrophobicity. I know you exist.)

The third family completing this wonderful collection of bizarre plants is the Proteaceae which have dried fruits/seed cases that look a bit like Donald Duck’s laughing beak mouth, cloned over and over and stuck on a pine cone.

Dried_banksia_flower

Quaaaack.

I find this picture hilarious, which probably tells you more about me than it does about the Proteaceae.

So how did this motley crew of families end up being one another’s closest relatives? Well, their order, the Proteales, is thought to be extremely old (120 million years old) so the idea is that it was once much more diverse but over time all the other groups have gone extinct, leaving only this handful of fabulous, flamboyant survivors.

References:

http://www.mobot.org/mobot/research/apweb/orders/protealesweb.html (for the botany geeks)

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The wasps do WHAT?

Figs. Their leaves have acted as preservers of modesty for millennia, they are lovely with Parma Ham and nothing beats a fig jam and soft cheese breakfast wrap (honestly, food of the gods). They are also sex dungeons.

Sex dungeons for wasps, that is. Well, perhaps ‘procreation dungeons’ is a better description but that doesn’t have the same ring to it. Fig wasps have a complicated and fascinating relationship with their fruity boudoirs and I’m about to go into the saucy details.  A small warning, you may never be able to look a fig in the eye ever again.

Firstly, let’s clear up what a fig actually is. Imagine a Daisy. Daisies are made up of lots of tiny, individual flowers in one big ‘pseudanthium’ (or ‘false flower’ for those of us who weren’t classically educated). Turn said Daisy in on itself, stitch up the edges and you have what is basically a fig. This structure is called a syconium and contains many tiny flowers. There are always 3 types of flowers; male, fertile female and sterile (gall) flowers. For the purposes of this explanation we’re going to assume they’re all in the same fig, although often they can be in separate figs (as we’ll see later). At the top of each fig is a little opening through which a female fig wasp, let’s call her Momma Waspy, can crawl. She fertilises the female flowers with the pollen from her mother fig and lays her eggs in the gall flowers.

Once the eggs hatch out, the males and females mate. In some species, males hatch out first and, in what apparently passes for good manners in the insect world, use this opportunity to fertilise their unborn female roommates before they hatch. These noble gents perform one last useful act of burrowing out of the fig leaving holes through which the females may later emerge and then, having fulfilled their evolutionary function and hence finding themselves useless, promptly drop dead. When the females hatch, possibly already fertilised, they get a dusting of pollen from the male flowers in the fig (yet more male gametes foisted upon them) and crawl out into the world to continue what is rapidly coming to resemble a particularly nasty story line of East Enders.

This is a picture of a fig I took in Indonesia. It had been chewed on by a Bear Cus Cus. I like to think that you can see the remains of a Momma Waspy near the top, but that may just be dirt.

This is a picture of a fig I took in Indonesia. It had been chewed on by a Bear Cus Cus. I like to think that you can see the remains of a Momma Waspy near the top, but that may just be dirt.

‘But’, I hear you cry, ‘What am I eating? I don’t know any more! I don’t think I even want to know!’ which is entirely understandable, seeing as figs appear to be nothing short of sordid pits of vice, and no one likes eating those. Luckily, however, most of the figs we eat are either parthenogenic (not needing fertilisation) or consist of only fertile female flowers. In these figs, Momma Waspy pushes her way in, fertilises the female flowers but finds no gall flowers to lay her eggs in. Disaster! And there’s no escape; the act of getting into the fig through the narrow hole has removed her wings and antennae so she’s effectively trapped. The reason we don’t find these poor, blighted creatures inside our figs is because the fruit produces enzymes which digest her. Yes, that’s right. Digest. Isn’t nature beautiful? So you might eat a bit of wasp (or wasp juice) along with your figs, but it was probably worse for the wasp, really.

Evolutionary biologists love figs and fig wasps as they’re a nice example of co-evolution. The wasps can’t live without the figs and vice versa. Apparently the syndrome first evolved around 80 million years ago and has diversified ever since with there now existing hundreds of different species of fig wasp and fig tree. I’ve only covered a tiny proportion of the huge diversity within this mutualistic freak-show, and the evolutionary theory behind it all is really quite cool (and complicated) so if you want to read more, here are some fun and useful links:

http://science.howstuffworks.com/zoology/insects-arachnids/fig-wasp.htm

http://www.wildsingapore.com/wildfacts/plants/others/ficus/ficus.htm

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What do ketchup, cigarettes and Harry Potter have in common?

They all contain members of the Solanaceae! Ok, ok, boring plant word but bear with me.

Tomatoes, Tobacco and Mandrake (the screaming humanoid plant roots? You know? The horrifying ones with the cries that can kill you? Based on a real plant. But more of him later) are all from the Solanaceae. It’s a family which contains nice, seemingly friendly plants like the comforting, starchy Potato and its delicious partner in crime the Tomato, but also things like Deadly Nightshade which ladies used to use to make their pupils dilated and 10-20 berries of which can kill a fully grown human. Not so comforting or delicious.

(A brief aside: when I use the term ‘family’, that basically means that the species in that ‘family’ group are more closely related to other species in the family than they are everything else. Ultimately, of course, they’re related to all other plants ever but it’s convenient for us to put things in boxes and Botanists love boxes almost as much as we love obscure Latin terminology.)

But anyway, back to the Solanaceae.

Deadly nightshade is not just, as its name suggests, deadly, but also pretty freaky. It has been used as an hallucinogen for centuries. It can make you believe you’re flying or that you’re an animal. It is also thought by some to have aphrodisiac properties but take the wrong dosage in the wrong way and you could find yourself with insomnia, ‘dry mucosa’ or possibly dead from respiratory arrest. Sexy.

And now the Mandrake. You’ve read Harry Potter and know all about it killing you with its screams if you haven’t got your ear muffs on, but as you also know if you’ve read any Medieval manuscripts (don’t deny it), this is based upon a very real, very mythical plant, Mandragora officinarum. People used to believe it had magical properties so powerful that it had to be harvested by letting dogs pull it up, or during certain phases of the lunar cycle or, just to be on the safe side, both. It was not a plant to be messed with.

Sadly, it doesn’t scream when you pull it up but the reality is possibly even more unpleasant. It used to poison people on a fairly regular basis back when salads were foraged from hedgerows and not everyone could tell their Brassica (cabbage) from their Mandragora. It likely also killed plenty of people who attempted to use it as a recreational or medicinal drug. Symptoms culminate in death by paralysis, which is nasty enough, but on the way you pass through nausea, vomiting, mydriasis and inability to speak. Somewhere in there are hallucinations and euphoria, but would you really want to risk it?

File:Mandragora dibujo.jpg

These guys wouldn’t, and they’ve got it growing out of their heads. (The roots of Mandrakes tend to have lots of limbs, which some people over the centuries decided meant they looked like humans, hence this old illustration). Image from Wikimedia commons as I sadly don’t have any of my own pictures of Mandrake.   http://commons.wikimedia.org/wiki/File:Mandragora_dibujo.jpg?uselang=en-gb

Finally, the humble potato. You know, the nice guy of the family. Eat its leaves, and you could find yourself in a coma. So don’t.

The cause of all this botanical brutality? These plants contain chemicals called alkaloids such as Scopolamine (the one responsible for the flying hallucinations), Hyoscyamine (hallucinations which last for days and central respiratory arrest) and Atropine (‘internal secretory disturbances’, which sound highly unpleasant, and reduction of cognitive capacity). These chemicals can also have some useful applications, for instance, as sedatives (in the right doses!) but are generally pretty damned dangerous.

So next time you order chips, have a Bloody Mary, eat Peppers or encounter those slightly odd orange things fancy restaurants like to put on your melon fan, remember that they are from the Mafia of the plant world. The badass, poisonous, mythical Solanaceae.

References and a warning: Most of the information in this post comes from the excellent book ‘Mind-Altering and Poisonous Plants of the World’ by Wink and Van Wyk. I’d recommend it. HOWEVER, I would NOT recommend that anyone in any way attempts to experiment with any of these plants. The bad consequences far outweigh any fun ones and you’d likely end up feeling very silly in A&E being pumped full of god knows what and attempting to explain to some exasperated doctors why you are essentially a medieval witch. Or just very, very dead.

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Moss is sexually active and you just need to accept that.

Moss could possibly be accused of being a bit, well, un-exciting. It doesn’t run about, it doesn’t maul things and it certainly doesn’t keep us awake at night with its mating calls.

But it does have sex.

And no, I don’t mean the usual pollen-lands-on-stigma, fertilisation happens behind closed doors, vaguely Victorian ‘higher’ plant sex. Moss sex is down and dirty (literally). It has swimming sperm which have to trek from the structures they’re produced in, the Antheridia (or ‘Moss testicles’ if we’re being anthropomorphic here) through a layer of water on the soil or the body of the plant or both, to reach the Archegonia (ok, just use your imagination) wherein they may find eggs, fertilise them and receive +10 Genetic Diversity Points for achieving sexual reproduction.

This is all fine and dandy and pretty cool, but the best thing about moss sperm is that you can see it under a microscope! I know this because I may or may not have spent an entire practical exclaiming variations on the theme of ‘OH MY GOD, IT WIGGLES! IT’S SO CUTE!’. My friend Peter, who is particularly good at coaxing sperm from Bryophytes (you can find him on Twitter @PeterMoonlight and admire his lovely photographs here), managed to film some. Therefore, here for your delectation and delight (no disgust, please, it’s perfectly natural) is a video of moss sperm, wiggling about like tiny green jelly beans with tails, searching in vain for Archegonia that they’ll never find (although most seem to be spinning aimlessly in circles, but I understand that’s pretty standard sperm behaviour). Tragic, really.

(Regarding their exact size, I am not entirely sure as Peter can’t remember what magnification he was using but I’d imagine in the order of 0.1mm would be a reasonable guess, please feel free to correct me if I’m wrong!)

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