23 December 2009

Author guidelines: what's past is prologue

Last-minute Christmas shoppers are braving the snow and slush outside. I remain sequestered indoors, braving the labyrinthine folds of my own brain. I nurse mug after mug of rooibos, procrastinate by baking these, distract myself by reading that. I find myself at the interface between two parts of my research, you see, and it has taken the form of a mental chasm I am hesitant to traverse.

In reality, I feel most fortunate to have made it this far. New insights into molecular biology are invariably gained using The Scientific Method, and my PhD research has been no exception. The first step is identifying a problem. In my field of study, the problem is that cereal plants manage to protect themselves against the ravages of insect pests, but we don't know how.* The next step is formulating a hypothesis that would address the problem, or some aspect of it. I therefore devised some gene-silencing experiments to test my hypothesis. I spent months in the lab, weeks in the greenhouse and tons of grant money. Most likely, I also inadvertently ate a couple of research subjects (aphids are small). I generated massive amounts of data, crunched the numbers, scrutinized the images, drew the graphs, did the statistics. I spent many hours in helpful discussion with my advisor. And now comes the next step in The Scientific Method: publishing the results.

Ever since I was a child, I knew I wanted to help figure out how the world works. I wanted to add pieces to the puzzle, somehow contribute to our understanding of life itself. Today, I'm fulfilling that dream by investigating the wonderfully complex machinery inside cells that help genes to function. Being a geneticist, with a focus on cereal functional genomics, means the pieces I contribute to the puzzle of nature are rather specific. It all seems rather small. I tend to get caught up in the detail of it. The detail is fascinating, certainly, but sometimes it feels kind of trivial, or unimportant. But then I read Michael Pollan, or about Norman Borlaug and the Green Revolution, or about golden rice, or the looming Ug99 epidemic, and I realize that what I do has tremendous value to world food security. What I do will help feed the world.

That's enough reason to get the word out and publish that paper. It is the final step to The Scientific Method. It also proves one of the most challenging. Which publication does one aim for? Should I be arrogant and aim for a high impact journal, with a very real chance of being rejected? Or do I aim for more a modest periodical and run the risk of my work falling into obscurity? Judging the worth of one's own research is really difficult, especially when you've been intimately involved with it for such a long period of time. The peer-review system ensures that only science of high quality gets published. It also means that the reviewers can be quite brutal, sometimes subjecting your raw data to a full-on audit, of sorts. So I need to be sure before I submit the manuscript. Was the experimental design inherently flawed? Did I include the appropriate controls during gene suppression? Did I transpose a decimal in a calculation somewhere? Are the levels of gene expression truly significantly different between treatments? Alone at night, huddled over my notebooks and spreadsheets, there are moments where I doubt myself. This I have no doubt about, though: with the right kind of angle, this thing will go to press. It deserves to. The story must be told. Without the smallest piece, no puzzle is complete.

And once all of it's over and done with, it's merely chapter one. Further hypotheses and fun in the lab to follow...

*More specifically, we know that so-called resistance genes allow plants to detect the presence of pests such as aphids, and act accordingly. Cereals like wheat can strengthen their cell walls, generate noxious chemicals like hydrogen peroxide - a sort of natural bug spray, if you will - and even kill off their own cells around aphid feeding sites, thereby depriving the bugs of their food supply. What we don't know is how plant defence mechanisms evolved. Nor do we know how they coordinate this massive reprogramming of their biochemistry. Some crop varieties are very good at it, while others do nothing to stop aphids from feeding on them and eventually just wither and die. We don't currently understand why this is the case.

16 October 2009

Pimp my petals: the Denver orchid show

There was snow along the highway as we headed for Echter's Garden Center in Arvada. The Denver Orchid Society Fall Show promised to inject some tropical colour into a rather dull October afternoon. The theme was 'Orchids of the World', and I was pleasantly surprised by the diverse amount of species on display. The usual suspects were of course chosen as class winners in their respective alliances: an electric blue Dendrobium victoria-reginae, a denizen of mossy oak forests in the Philippines;

a vibrant
Ascocenda Su Fun Beauty, its petals the colour of overripe persimmons;

and Paphiopedilum Magic Lantern 'Memoria Elizabeth Sulzman', holding its pouch as if the plant itself had just blown it from pink bubblegum. Feed me, Seymour, indeed.

Many strange and unusual specimens were on show, to the delight of jaded orchid enthusiasts bored by saucer-sized vandas and over-hybridized cattleyas. This South American
Zootrophion below is a prime example of the bizarre orchids on display. Its small cage-like flowers don't open fully, and are covered in tubercules. What sort of minute insect is brave enough to crawl inside these to pollinate them?

Cleisocentron merrillianum is an astonishing little beast from Borneo: its slate grey flowers had many visitors to the show fiddling with the macro settings on their cameras.

Easily overlooked,
Eria coronaria had its flowers hidden away in lush green foliage. This fragrant species has a wide distribution and can be found from the Vietnamese coast all the way to the foothills of the Himalayas.

This sinuous monopodial with subtle chartreuse coloured blooms is called
Christensonia vietnamica. It originates in Vietnam - as should be obvious from its name - but curiously was unknown to science until as recently as 1993! It was a real treat to see a newly discovered species thriving in cultivation.

As usual my favourite thing on show is a dendrobium - usually a crystalline white Formosae-type with little black hairs on the canes, or a candy coloured jewel from New Guinea. This time
Dendrobium bracteosum won me over: masses of waxy flowers emerging from papery bracts on the pendulous canes. This New Guinea native positively froths over with blossoms, each dotted with a rather impudent splash of tangerine on the lip.

Although I've been awfully good since living in the States, this time around I just couldn't help myself. The lure of the sale tables was just too strong, and I bought my first (non-
grocery store Phalaenopsis) orchid since moving to Colorado in 2007. I managed to get a totally sweet deal on a Psychopsis Mendenhall 'Hildos' from Oak Hill Gardens. The clone I obtained, 'Hildos, has been awarded a First Class Certificate, the highest award bestowed by the American Orchid Society. So I got a great looking plant from awesome genetic stock for less than the price of a steak dinner. Below is a photograph of a similar orchid that was on show: Psychopsis Mendenhall 'Lace' x Psychopsis Mem. Bill Carter 'Mendenhall'. Are you jealous yet?

I have many more images from the 2009 Denver Fall Show and previous orchid shows available in glorious Technicolor™ on Flickr.
Check it out.

7 September 2009

Grad school has swallowed me alive

Yes, I'm still alive. And doing rather well, thanks for asking. Unfortunately grad school has become my whole life this past month or so. I have been silencing genes and counting aphids until it feels my head has been drained of grey matter and stuffed with balls of cotton wool. There are several new stories carefully packed in that cotton wool, of course, but you will just have to be patient with me. In the mean time, here are some images from my research, to tide you over until the next proper installment of (E&E)². The top image shows 3,3'-diaminobenzidine staining in a leaf of resistant wheat after feeding by aphids has caused the massive release of peroxides. The bottom aniline blue image is of callose deposits that strengthen cell walls in response to the little suckers.

Sometimes sciences can just be about pretty pictures, can't it?

1 August 2009

Ambergris: perhaps you'd rather not know

I combed the beaches of St. Francis Bay with my aunt one afternoon, now a lifetime ago. The weather was nasty; it had been raining for most of the day. We didn't mind, of course, since we knew that stormy weather brings the secrets of the sea ashore. That was the day my aunt found the giant eggcase of a paper nautilus, wedged between the rocks. The perfectly white, rippled object was the most gorgeous and delicate thing I had ever seen. I believe that was the first moment my impressionable young mind was filled with a sense of awe at the mysterious creatures that live in the liquid parts of the planet.

Some things that wash ashore are less obviously beautiful: broken jellyfish, reduced to lumps of snot; kelp fronds; dead gannets; ambergris. Ambergris? Yes, ambergris, the stuff of myth and poetry. Sounds romantic, but what exactly is it? Read on, although the story isn't for the squeamish. Sometimes, when something is so... biological in origin, it is perhaps better to live in ignorance.

The sperm whale is the largest predator to have ever existed. It dives to almost three kilometres below the surface of the ocean in order to do battle with giant and colossal squid in the inky depths. Although sperm whales also feed on fish, they are particularly fond of cuttlefish and squid. The problem with a diet high in cephalopods is that those sharp squid beaks are not exactly digestible. So in a process analogous to how a pearl is formed in an oyster through constant irritation, the whale encases these beaks and other indigestible matter in fatty secretions from its digestive system. These lumps are then easily excreted by the whale, without fear of internal nicks and scrapes.

Many people refer to ambergris as "whale vomit", although Hal Whitehead, a whale scientist of Dalhousie University in Halifax, Nova Scotia, is of the opinion that ambergris is more likely excreted via the faecal route. Not to worry; I won't go into much more detail concerning cetacean scatology. The interesting part of the ambergris story concerns what certain land living bipedal primates elect to do when they find the stuff washed up on the shores of the world. Tar-black and viscous, freshly expelled ambergris is strikingly foul-smelling. However, a counterintuitive thing happens when these lumps drift around in the ocean, exposed to sunlight, oxygen and salt water. As ambergris oxidizes, it begins to cure and harden. Well-aged ambergris has a waxy texture and is marbled grey in colour. In fact, the word ambergris is derived from the French ambre gris, meaning grey amber.

The smell of ambergris fortunately also changes with ageing. People try in vain to describe its depth and complexity, but fail. In the end, ambergris smells like ambergris and there's nothing quite like it. It is sweet, but dangerous. It has earthy notes, like tobacco, mulch or mossy pine forests combined with marine notes like sea spray and ocean breezes. But it also exudes something that belies its animal origin: musk, leather and something altogether mammalian. Like the flowers of jasmine, it retains a definite faecal undertone. The elaborate chemistry of ambergris consists of countless compounds, and is particularly abundant in steroid lipids. The most important of these is a molecule called ambrein, pictured here. Ambrein is oxidized during the ageing process, to form several related pungent compounds with names that make them sound rather like the heroines of forgotten Victorian bodice-rippers: ambrox, ambroxide, coronal, ambrinol... It's the combination of all these molecules together which is responsible for the complex fragrance of ambergris.

Gross as its origins are, ambergris has been a highly valued commodity for centuries. Reknowned in China before the year 1000, it was known as lung sien hiang, meaning "dragon’s spittle fragrance," because it was thought to be the saliva of sleeping sea dragons drooling into the ocean. During the Renaissance, small lumps of ambergris were moulded into decorative jewelry. It was ceremonially burned, like incense. It has since found particular use in the perfume industry as a fixative. It retains other fragrance ingredients, preventing their rapid evaporation and allowing the scent to linger on the skin. One classic method for preparing an ambergris extract used "1½ oz. of ambergris, 30 grains musk and 20 grains civet reduced to powder in loaf sugar," to which was added the juice of 1 unripe lime. This was poured into 3 pints of pure spirit alcohol and placed in a stoppered jar. The jar was incubated in "the constant heat of horse manure for 21 days," and the resultant clear, amber-coloured liquid decanted as Tincture of Ambergris. Perfumiers today rely on more scientific methods of extraction, or have switched to using synthetic alternatives. However, real ambergris is purportedly still an important component of such famous fragrances as Chanel No. 5 and Drakkar Noir.

The quality of ambergris depends on how long it has been floating around the ocean. Just like wine it mellows with age, and increases in value. Standard grade ambergris trades at almost $20 per gram. Considering that ambergris is sometimes found as giant lumps weighing hundreds of kilograms, finding ambergris on the beach can be quite lucrative. Since ambergris resembles a smelly, shapeless lump of sea detritus and not the delicate eggcase of a paper nautilus, most people ignore it witout realizing its value. Pieces of the fragrant flotsam are often sold for tens to hundreds of thousands of dollars to so-called "ambergris brokers". The trade in ambergris seems slightly shady: deals occur behind closed doors in hotel rooms in places like Dubai and Abu Dhabi, and purchases are always made in cash. Just a few people control the world ambergris market, and I suppose they would like it to remain that way.

Through the ages, ambergris has not solely been used for perfume. Its animalistic allure had much further reach. In fact, it formed a vital part of the traditional pharmacopeia of many cultures around the world. It was lauded as a restorative balm. Arab doctors prescribed it as heart and brain medicine. Perhaps not surprisingly, the sensual scent of ambergris was highly in demand as an aphrodisiac. Legend has it that Madame du Barry washed herself with it to make herself irresistible to Louis XV of France. Oddly enough, ambergris has been - and in some cultures still is - used as a spice for food and wine. Beluga caviar? White truffles? How gauche. Surely shavings of first grade ambergris on your eggs benedict must be an unparalleled epicurean billionaire's treat! Personally, I'm sure I could never stomach it. If it disagreed with the whale, it is certain to disagree with me.

Picture credits: paper nautilus © mrpbps; sperm whale © Brian J. Skerry; ambergris © composite from various sources; Chanel No. 5 © Andy Warhol, 1985; vintage perfume bottles © meeralee.

26 July 2009

"We should have been foaming at the mouth..."

It was late-July and the Rocky Mountain orchid season was drawing to a close. When two good friends, First Man* and CJ*, invited me to accompany them on a hike in the mountains around Breckenridge, I didn't hesitate. I thought this would be the perfect opportunity to go hunting for terrestrial orchids. I had visions of us locating great species, like the spotted coralroot, the roundleaf orchid, or perhaps the glorious yellow lady's slipper - if we got particularly lucky. Instead, what we managed to do was prove that even three plant scientists, armed to the back teeth with guide books, can still be quite naive and actually very stupid when left to their own devices in the wilderness...

The weather was absolutely perfect as we breached 11,000 ft. in the shadow of Quandary Peak. The mountain itself, highest in the Tenmile Range at 14,265 ft., was teeming with climbers trying to reach the summit. However, we weren't there to test our mountaineering skills. We were there to revel in the botanical splendour that is the alpine summer. When warmth and liquid water have been absent for so long, plants seem to put in extra metabolic effort to really make the most of these summer resources. Wildflowers were everywhere: columbines with their bi-coloured cups; whiproot clover hugging the scree slopes; violets; forget-me-nots; saxifrage and primrose shimmering on the banks of streams; red and yellow paintbrush; asters and monkshood competing to see who had the most intense shade of purple. And higher up, their petals shredded by howling winds, alpine sunflowers. I started to feel giddy from all the biodiversity around me. Or it may have been the altitude, it's difficult to tell. No sign of a single orchid, though. Were we too late? Had they all gone?

We rounded a corner on the trail and came across a stand of the most peculiar plant (
above). We stopped dead in our tracks. It was beautiful. Mid-green, pleated leaves bursting towards the sky from large clumps. We had to know what this thing was, taxonomically pin it down on the herbarium cards inside our heads. You could tell by the venation of the leaves that what we had here was a monocot. Which still meant it could be any one of around 60,000 species of plants. Was it some sort of lily? Or was it Cypripedium parviflorum, the yellow lady's slipper orchid? I so desperately wanted it to be the latter. Slippers are unmistakable in bloom, but this one didn't have a single flower on it. So as geeks do in situations like these, we whipped out the guide books. Mine had a lot of interesting text, but the pictures, frankly, were total crap. CJ's book contained more flower porn than you could shake a large stick at, so we elected to look through hers first.

Nothing. Couldn't find this thing at all. Looked through my book next, but to no avail. Mosquitoes started buzzing around our heads. It was time to move on. The trail was marked on First Man's GPS, so we could always come back this way if we didn't see it again. As we were hiking past stone cairns piled by previous explorers, CJ and I decided that it just might be an orchid, since the leaves looked so similar. Here's a picture of the yellow lady's slipper (left). Wouldn't you agree? Big, mid-green, pleated leaves. Identical. Especially because I wanted it to be identical. Which was a big mistake. We finally found another clump of the mystery plant. Against our better judgement (and park regulations, possibly) CJ and I waded into it. We stood waist-deep in the stuff. CJ caressed the leaves with her fingers, as I turned them upside-down to scrutinize the surprisingly hairy undersides. I almost suggested digging one up to look at its root structure (since terrestrial orchids generally have distinctive underground tubers), but luckily the environmentalist in me vetoed that idea.

Then we noticed the inflorescences. Two plants way in the back of the clump had the beginnings of enormous flower spikes forming, with lots of tiny, green undeveloped flowers forming. This was the evidence that shattered the fantasy. This was clearly no orchid, but something entirely different. In the end, we hiked all the way above treeline, to hidden lakes, and all the way back down again, without discovering any orchids. I had a truly terrific time, of course, but the orchid hunter in me was disappointed. We also failed to uncover the identity of the mystery plant, which was most unsatisfying. So that evening, after dinner and in the warm comfort of the cabin, we turned to every scientist's last resort. We Googled it.

Guessing that its colloquial name may have the word "lily" in it (don't they all?) I spent some time doing image searches with various forms of "lily" or "lilies" and "Rockies" or "Rocky Mountains". And then I found it: Veratrum californicum, the corn lily. Without a doubt. CJ and I excitedly grabbed our guide books again. Interestingly enough, the plant and related species were listed in both our books. The images were just really bad likenesses, so we had simply ignored those entries while on the mountain. Once again, a mistake, as we discovered when I read aloud from the entry in my book.

This plant, also known as the California false hellebore, is poisonous. And not just poisonous, the book informed us. Violently poisonous. "Eating even small amounts can result in unconsciousness, followed by death," we were informed. The symptoms of corn lily poisoning apparently include, "frothing at the mouth, blurred vision, lock-jaw, vomiting and diarrhea" and "people have reported stomach cramps after drinking water in which this plant was growing". Geez. We'd been waist-deep in them, touching their furry leaves. A brush with death, literally. Native Americans used to boil the roots and use the resulting extract to kill lice. I was suddenly very glad I had elected not to dig one up. Veratrum californicum contains the teratogenic alkaloids jervine and cyclopamine, which cause major birth defects such as cyclopia. Oh dear.

Just the week before, I had finished reading Wicked Plants by Amy Stewart - a beautiful and fascinating book all about spiky, toxic, invasive and poisonous plants. How ironic. I guess I learned two valuable lesssons on this trip. One: just because you want something to be true, it doesn't necessarily make it so. Two: assume every creature unfamiliar to you will try to kill you somehow. We so desperately wanted to find an orchid that we did things against our better judgement. Even in the mountains, orchids cast their crazy spell. Days later, when we'd all gone back to work, I noticed that CJ had changed her Facebook status to read, "After seeing the photos... we should have been foaming at the mouth".

*Names have been changed to protect the ignorant.

Photography credit: alpine meadow and Veratrum californicum © The Electric Orchid Hunter (that's me!); Cypripedium parviflorum © David Tees and Melanie Schori

31 May 2009

Wine me, dine me, finger lime me

These gorgeous things are becoming my new obsession. They are called finger limes and may well be the sexiest citrus fruit ever. I mean, just look at them! Their exquisitely elongated form echoes the shape of the banana and cucumber, those pedestrian fruit more traditionally associated with the erotic arts. However, when the skin of the finger lime is ruptured, all these sap-filled vesicles come bursting forth, an aromatic explosion of lime-tastic goodness. Am I crazy, or does that sound like a near-perfect description of culinary orgasm?

As you can tell from the scientific name,
Citrus australasica, the finger lime is native to Australia. It's a thorny tree almost 10 m in height, endemic to subtropical rainforests from northern New South Wales to southern Queensland. The genetic diversity latent in finger limes is evidenced by the huge number of varieties known. The peel colour is very variable and ranges from yellow to green, burgundy and almost black. Beat that, banana skins! The pulp also varies from palest pearl to deepest ruby, with each colour having a unique flavour all its own.

Finger limes are making real headway into the fancy restaurants and boutique grocers of the world, but I'm yet to find one of these tangy beauties anywhere near where I live. In the meantime, a boy can dream, can't he? They can be used in any dish that calls for conventional limes, and are particularly suited to seafood dishes or those with a Southeast Asian influence. With those zesty vesicles shimmering like salmon roe, it's no wonder they've been called 'rainforest caviar'. Imagine some of these added to your favourite after-work drink: instant jungle-style sophistication. Finger limes are especially prized in the world of molecular gastronomy. Ferran Adrià, chef of the fabled
elBulli restaurant on the Spanish Costa Brava, was apparently moved to tears by his first experience with finger limes.

That's okay: many people cry after their first time.

Citrus pr0n credits: top © El Aderezo; middle © Stuart Cohen; bottom © D.T. Pearson.

25 May 2009

The Kerguelen Cabbage

It was widely believed during the 18th century that a massive southern continent must exist in order to balance out the landmasses of the northern hemisphere. King Louis XV wanted to claim this Terra Australis for France, and commissioned Yves-Joseph de Kerguelen-Trémarec, an ambitious naval officer, to set out for the Southern Ocean in search of it and to establish trade with its natives.
       Braving stormy seas, De Kerguelen discovered an island wreathed in fog on February 12th, 1772. The island was midway between South Africa and Australia, and right in the path of the Furious Fifties: non-stop Antarctic winds that howled across its barren surface from the west. Wind speeds in excess of 150 kph drove waves as high as 15 m around its ragged coastline cut by fjords and inlets. No trees grew there; the interior was almost entirely covered by glaciers. After several expeditions - not all of which made landfall in the rough seas - it became clear that the island was uninhabitable and not the southern counterpart to France everyone had hoped for. Disillusioned, King Louis XV had De Kerguelen incarcerated at Saumur Château for almost four years. Conveniently for De Kerguelen, the French Revolution occurred soon after. Since he was regarded as a victim of the Ancien Régime, he was released and eventually became Rear Admiral and commander of the port of Brest. De Kerguelen died in 1797. But what became of his island, you ask?

On Christmas Day 1776, Captain James Cook anchored the HMS Resolution and HMS Discovery in a bay on an uninhabited island in the Southern Ocean. Cook decided to call the bay Christmas Harbour and the island itself Desolation Island. While Cook's men explored the shore, one found a bottle fastened with some wire to a projecting rock on the north side of the bay. Inside the bottle was a message, written in Latin by one of De Kerguelen's company, Officer De Rochegude of the French frigate L'Oisseau. The message claimed the island in the name of the King of France. Cook wrote in his log, "I could have very properly called the island Desolation Island… but in order not to deprive M. De Kerguelen of the glory of having discovered it, I have called it Kerguelen Land." 

And so Kerguelen Island was discovered and named. It remains a French territory to this day. Although the frozen continent of Antarctica was discovered in 1820, perhaps De Kerguelen was not entirely off the mark when he claimed that his island was Terra Australis. In fact, modern surveys of ocean floor topography have revealed that several islands of the sub-Antarctic Indian Ocean are actually the highest exposures of an ancient landmass which sank beneath the surface of the sea about 20 million years ago. This submerged landmass has been named the Kerguelen Plateau. Rich underwater coal seams have been discovered here, evidence of expansive forests that once covered this lost continent.

Captain James Cook and his men were exploring Kerguelen Island in 1776, clubbing seals on the shore and collecting fresh water further inland, when William Anderson, Cook's surgeon, came upon a most curious plant. He described it thus: "It was not unlike a small cabbage," having "not only the appearance, but the watery acid taste of the antiscorbutics."It did resemble the Savoy cabbage, but seemed to be a slow growing perennial, as evidenced by its long woody stem. The leaves of this Kerguelen cabbage contained a pale yellow oil, rich in vitamin C.  Having spent months at sea, Cook and his men staved off scurvy by supplementing their meals of seal meat with boiled Kerguelen cabbage. Boiling released all its essential oils, making it even more pungent, but the malnourished seamen took no notice of its strong taste reminiscent of watercress or horseradish. Anderson gave it its scientific name of Pringlea, after Sir John Pringle, who was president of the Royal society at the time.

The Kerguelen cabbage had to await the arrival of the Ross Expedition in 1840, before it received a full scientific description. Sir Joseph Hooker, assistant surgeon on the HMS Erebus, catalogued 18 flowering plants, 35 mosses and liverworts, 25 lichens and 51 algae during the Expedition's time on the island, but called the Kerguelen cabbage "perhaps the most interesting plant procured during the whole voyage in the Antarctic".  It was given its full name of Pringlea antiscorbutica, emphasizing its use as a remedy against scurvy. It provided much-needed sustenance to the crew of the Ross Expedition. As Hooker wrote: "During the whole stay of Erebus and Terror in Christmas Harbour, daily use was made of the vegetable, either cooked by itself or boiled with the ships' beef, pork, or pea-soup; the essential oil gives a peculiar flavour which the majority of the officers and crew did not dislike and which rendered the herb more wholesome than the common cabbage for it never caused heartburn, or any of the unpleasant symptoms which that plant sometimes produces." Hooker rightly predicted that the cabbage would be a blessing to future ships that passed by. 

In May of 1973, a letter from a curious reader appeared in the journal Nature, asking whether the scientists on board the HMS Challenger, then bound for Kerguelen to observe the 1874 transit of Venus, would try to collect seeds of the cabbage, so that it may be introduced on the shores of northern Europe and America. Because of its achingly slow growth and predilection for the cold, this feat was thought impossible. Recently, Canberra botanists have managed to successfully grow Pringlea antiscorbutica at the Australian National Botanic Gardens, demonstrating its commercial potential. Perhaps soon Kerguelen cabbage will be de rigueur on the menus of fancy restaurants the world over. Peppery Kergeulen cabbage with smoked salmon and lemon vinaigrette – an acquired taste, I’m sure.

Contrary to its common name, the Kerguelen cabbage is not restricted to Kerguelen Island. It grows on several sub-Antarctic islands, including the Crozet Archipelago, Heard Island, the McDonald Islands, and the Prince Edward Islands. Because of the non-stop strong winds, these islands don't have any winged insects. The Kerguelen cabbage, which is indeed related to the common cabbage and other crucifers, has therefore evolved to be wind-pollinated. It has also evolved to produce high levels of compounds called polyamines in its leaves, which act as a natural antifreeze. 

The 1874 Challenger expedition to Kerguelen brought rabbits from South Africa with it. These would serve as a food source for the sealers and whalers that regularly passed by the area. However, with no natural enemies, the rabbit population exploded, causing severe erosion and unprecedented damage to the island’s plant life.  Where rabbits grazed, plants like the Kerguelen cabbage and the cushion plant (Azorella selago) quickly became rare. The Kerguelen cabbage seemed destined to survive only on small offshore islands free from rabbits. The rabbit myxoma virus was introduced in the 1950s in an attempt to control the population. The rabbits rapidly developed resistance against the virus. It gets worse. Climate change is hastening the spread of plant species introduced from warmer environments. In 2004, a rabbit removal study indicated that the rabbits on Kerguelen Island might now be a necessary evil, required to keep the spread of such exotic plant species at bay. 
       Kerguelen and its surrounding islands are now home to rabbits, rats, mice, cats, sheep and reindeer. Rats and mice eat the seeds of native plants unchecked, since the cats seem more intent on catching seabirds than vermin. Reindeer consume all the slow-growing lichens. Sheep trample the meadows where cushion plants used to provide shelter for albatross nests. Intentionally or accidentally, we are responsible for the introduction of these creatures. What will happen to the Kerguelen cabbage, this wondrous vegetable that saved the lives of so many sailors in centuries past? 
       What have we done to Terra Australis

Image credits: Kerguelen Island © Pascal Subtil; 'View of Christmas Harbour' by John Webber (1776) © British Library; 'Pringlea antiscorbutica' by Joseph Hooker (1844) © Linda Hall Library; Kerguelen cabbage in situ © Station Alpine Joseph Fourier; and © Australian Antarctic Division.

21 May 2009

Like a bud bursting with renewed vigor

It's late Spring. The Chelsea Flower Show is happening right now, which makes for great inspiration in the garden and greenhouse. Best of all, my preliminary exams are finally over. Yes, folks, I have qualified and am now a 'Ph.D. candidate', whatever that means! More frequent posts will hopefully result from my - slightly - more relaxed summer schedule.

Hope to see you all soon!
- orchidhunter

29 March 2009

(E&E)² tales: The summit of Mount Mabu [4/4]

It had been raining heavily all night long. Leaves glistened in the stifling understory; mist rose from the damp ground. Alan’s backpack was soaked through and the Garmin GPS kept cutting out, making it difficult to pinpoint the coordinates of some of the plants they collected. He was secretly glad when Olivia stopped to refill her water bottle. Above them, insects throbbed their mating calls on the limbs of trees. His quads burned from climbing uphill virtually non-stop for two days. The things he’d seen. He was teetering at that narrow interface between exhilaration and exhaustion.

The site was amazing: 7,000 hectares of virtually unexplored medium-altitude forest. The only access road ended several kilometers away at a disintegrating tea estate, long abandoned. They had left the Land Cruiser among the collapsing ruins and hiked the rest of the way. The name Mount Mabu does not occur in classic plant collection records from northern Mozambique. After decades of civil war, local people were only now returning to the area. Most were unaware that the mountain even had a name. And now the scientists from the Darwin Initiative had already collected more than 500 different specimens of plants and animals here. They’ve done pretty well themselves, Alan thought. He’d recorded almost thirty succulents so far, and collected a number of specimens. If only he had coordinates for all of them. Cataloguing is going to be a nightmare when he got back to UCT. Olivia was growing more sullen with each step, though; there was still no sign of the Polystachya orchid. She’d hardly spoken a word in the last four hours.

Olivia straightened. ‘My God, Alan, a huge snake,’ she said levelly.

‘Just stand back and don’t bother it,’ Alan responded. ‘Just let it pass.’

‘I think it’s dead, actually. This big guy isn’t going anywhere.’

‘Are you sure it’s not just playing dead?’ Alan exhaled, slowly.

‘It’s a Gaboon viper, Bitis gabonica. I don’t think thanatosis is in its repertoire.’ Olivia meticulously stripped the leaves off a fallen branch. ‘But massive amounts of haemotoxin is,’ she continued. ‘They’ve got the largest fangs of any venomous snake. Here, look.’ With this she forced the dead viper’s jaws open with the end of the branch. At the lips and especially surrounding the giant fangs, the inside of the snake’s mouth was studded with glistening brown ticks. Alan wanted to look away. ‘I guess it must have died of infection,’ Olivia said, dropping the branch. ‘Ticks are vectors for all sorts of diseases.’

In a nearby sycamore fig with peeling yellow bark, samango monkeys twittered like birds. Elephant shrews scurried around in the dark, somewhere in the underbrush. A chameleon jerked and staggered towards a mantis, actors in their own silent film. The blue and brown discs of bracket fungi were slowly decomposing a fallen trunk, already in the shadow of saplings that raced skyward to fill the tear in the canopy. It was so hot. This forest seemed inordinately alive. Metabolic. More so than any place Alan could remember from previous fieldtrips. It was almost unimaginable that somewhere outside this verdant realm people busied themselves with their own cycle of birth and life and death. Nurses administered drugs to expectant mothers so that their unborn children wouldn’t share their fate; teenage heads of households sold scrap metal on the dusty streets of Mozambique’s villages; men woke up in the dark to stand in line outside clinics, not aware that their tuberculosis is multidrug-resistant; women planted maize where Renamo militia once planted landmines. Alan thought of all this as he clambered over lichen-covered boulders after Olivia, who was randomly taking photographs. Suddenly they broke through the canopy at the summit of Mount Mabu, and the light was bright, and there were white butterflies everywhere.

The forest they had traversed rolled into the distance beneath them. Above, every layer of the sky was filled with small white butterflies. Some of them were so high up, lifted by air currents, that Alan couldn’t be sure whether they were butterflies or just floaters in the vitreous humour of his own eyeballs. It was quiet. Millions of minute wings flapped continuously, soundlessly.

‘Mass migration,’ Olivia said from a nearby rock. ‘They’re all heading northwest.’ Alan didn’t say anything. For in the back of his mind, an awful thing had sprouted. A parasitic thought had innervated his brain, like dodder inserts itself into the vessels of a host plant. I am going to die here, he thought. In that very moment, their whole excursion seemed like such a dreadful mistake. Planned in secret, organized in haste; the head of his department didn’t even know that he was gone. Was he really that arrogant that he thought this would work? He’d never done anything this impulsive before, and suddenly it terrified him. He was getting sick, he knew. Even with the heat and the humidity, he knew that he must have a fever. He awaited the quivering of his soft palate, that gentle prickling at the back of his throat that heralds the onset of symptoms. It was just a question of time. He had to hide it from Olivia. Avoid panic. Don’t let her know -

‘Dr. Schroder!’ Alan looked up. He had a vague notion that Olivia had been calling his name for quite some time. ‘I said, I’ll give you the photos, so you can share them with Daniel. We may never see such a thing again. Marvelous creatures, insects.’ It was late afternoon, and the butterflies had not stopped. ‘I’m just a bit disappointed that we never managed to find a Polystachya songaniensis. We recorded so many natural clearings and stream banks. I really thought those would be prime habitat.’ Olivia sighed. ‘Perhaps it just doesn’t occur here after all.’

‘Yeah,’ Alan ventured. ‘Perhaps you’re right.’

‘I guess I could always try and get DNA from one of those epiphytic orchids you collected earlier today. What was it, Mystacidium?’

Aerangis. But I’m not sure of the species.’ The wind started to pick up. The heads of thunderclouds were abuzz with lightning on the horizon to the north. Another wet evening was coming. What do butterflies do when it rains? he wondered. ‘Listen,’ Alan said and cleared his throat. ‘Don’t you think we should start looking for a suitable spot to make camp? It’ll be dark sooner than we think.’

‘Alright,’ Olivia said, strapping on her backpack. ‘Let me just take a picture of those clouds.’ She stepped right up to the edge of the summit, her eyes fixed on the screen of her camera. ‘The light is really good right now.’ And with that Olivia slid on some loose rocks and plunged down a ravine.

To Alan it seemed like he was watching it from outside himself, from a viewpoint away from the summit, somehow suspended next to the mountain in mid-air. He watched as she fell several meters towards a rocky ledge. He watched as her left ankle was jammed between large boulders studded with aloes, their succulent leaves sparkling like jade in the afternoon glow. He watched as the momentum of her descent swung her around, pivoted her around her jammed ankle with an audible snap of bone and tendon. He watched as her skull connected with the rock of the cliff. He watched all of this from outside himself. A few seconds of quiet. Olivia’s camera smashed into pieces at the bottom of the ravine. Alan’s next thought was that he would now never be able to share the butterfly migration with Daniel.  The weight of her backpack wedged her ankle firmly into the crevice. Olivia hung down there, out of reach and limp, like someone who had been crucified upside-down. Unconscious? Dead? Alan had no way of knowing, and no way of getting to her.

It was all such a dreadful mistake. Shouting her name had no effect. Alan had to get off the mountain as fast as possible, seek help. He did the only thing he could think of: he ran. It didn’t matter that it took them two days of hiking to get there from where they left the Land Cruiser. It didn’t matter that the nearest civilization was half a day’s drive away. It didn’t matter that his skin was ripped by thorns and branches slashing at him as he ran. Nothing mattered, apart from his muscles propelling him down the jungled slopes. He tried to ignore the soreness at the back of his throat, tried to ignore the swollen lymph nodes down the side of his neck. This is how you die, Alan thought. Not in a car on the highway. Not on the treadmill in the gym. Not in a comfortable bed, surrounded by people you love. This is how you die: small and alone in the woods, by claws and venom and poisonous sap. Viruses wait in the dark forest for you, have been waiting for thousands of years for people to come and reawaken them and absorb them and take them to the cities.

It was dusk when Alan ran into a forest clearing. Alan stopped to catch his breath and take a drink. It was a rocky patch next to a stream, populated by grasses and aloes. The soil was too shallow for large trees here. Growing between the rocks, almost hidden by tall grass, Alan saw the orchid. From Olivia’s descriptions and botanical illustrations at the Compton Herbarium, it was undeniably Polystachya songaniensis. None of that seemed to matter now. Rosettes of green leaves supported tall inflorescences with several small blooms. They were everywhere in the clearing, all around him. For some reason, Alan had assumed the flowers would be blood red, but they weren’t. The flowers were pink.


Image credit: Road to Mount Mabu © Julian Bayliss, Kew. Read more about the real expedition to Mount Mabu here.