Sunday, May 31, 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.

Monday, May 25, 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.

Thursday, May 21, 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

Sunday, March 29, 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.