Chapter 7
THE LIVING TREES

On 15 December 1994, the day after the Sydney Morning Herald announced the discovery of the Wollemi pine, I published a second story on the tree—this time about the fact that Sydney’s Royal Botanic Gardens had possession of a seedling which they would study in order to learn how to propagate Wollemia. Jones had collected the seedling from the site.

This first living Wollemi pine to leave the canyon was shorter than a man’s thumb and had a trunk thinner than a matchstick. It was whisked straight into the tightest security that botanists can muster and it would be another four years before a Wollemi pine would be placed on permanent public display. During those first twelve months visitors with clearance to view the trees in cultivation were unable to enter the glasshouse in which they were growing. Instead a Wollemi pine would be fetched from its security for a brief showing as if it were some kind of family treasure. On one occasion a seedling was brought out for a photographic shoot for the Herald. That little tree was one of four Wollemi pines in cultivation that had begun its life in the canyon. It was being carefully prepared for the camera when the stand on which it was resting collapsed. The pot crashed onto the lab floor, sending the Wollemi pine sprawling. For a few seconds there was silence as the shock registered. Then the tree was replanted. Today it is one of the healthiest and most mature of the Wollemi pines in cultivation. It has started to develop its distinctive bubbly bark, stands at more than two metres tall and, like a teenager in need of a haircut, is covered in shocks of prehistoric-looking foliage.

In the wild a Wollemia seedling has almost no chance of surviving to adulthood—its two main enemies are darkness and crowding. As part of the research effort in the canyon all seedlings located are tagged and numbered.

Jan Allen’s partner Rob Smith requested that cuttings be collected from Jones for propagation at the Mount Tomah gardens. By November 1994 roots had struck from this material. But the main propagation effort began a month later at the Mount Annan Botanic Gardens from other cuttings. The program was rapidly intensified as the botanists realised they were racing against time. Until the trees were available in nurseries the wild population Noble had found—twenty-three adults, a handful of juveniles and an unknown number of seedlings—was in grave danger. Helicopter searches in nearby canyons and up and down the gorge where the pines had been found failed to locate any other stands of the trees.

Just as there are two types of scientists who study the trees—those who study their fossils and those who study living ones—there are now two types of Wollemi pine: wild and cultivated. After millions of years of solitude Wollemia nobilis hit one of the most significant forks in the road that it had ever experienced. It is the job of Cathy Offord, a horticultural scientist at the Mount Annan Botanic Gardens, an annexe of Sydney’s Royal Botanic Gardens, to ensure that the new road is as smooth as possible. Offord grew up in western New South Wales and her parents were the kind of people whose imaginations had been captured by the discovery in 1948 of the dawn redwood. But the dawn redwood has become the bane of Cathy’s life. As the scientist in charge of cultivating Wollemi pines, people are constantly asking her, ‘Why is it taking so long to propagate the pines compared to the redwoods?’

Dawn redwoods are now grown everywhere—within months of their discovery botanic gardens around the world were sent seeds and seedlings. In fact, even before Chaney and Silverman tracked down the trees in China, Chinese botanists had in 1947 already collected seeds and distributed them to colleagues overseas for propagation. But by the time of Chaney and Silverman’s expedition in 1948 these seedlings were not big enough for scientists to realise their significance. After his visit, Silverman returned to the US with his pockets stuffed with seeds. Chaney also took 25,000 seeds. By February of 1951 he was able to report to his counterparts in China: ‘From the seeds I have brought back with me, I have propagated several thousand seedlings. These have been distributed widely over North America and some of them are successfully growing as far north as Alaska.’

The fact that it is so hard to collect Wollemi pine material means that little is known about its life cycle. But the propagation team decided that the benefits in immediately beginning a program of harvesting seeds from the trees far outweighed the risks. In the first year a mere fifty seeds were collected. In the second a more promising quantity was obtained—600.

The seed-cones of the Wollemi pine cannot be collected by climbing the trees because not only are they right up in the flimsy crowns, they are also at the very end of extremely long thin branches. Initial seed-collecting strategies considered included using trained monkeys to retrieve the cones as well as gas-filled balloons called ‘dirigibles’. The only method so far devised to successfully obtain the seed-cones is a refinement of Wyn Jones’s—to dangle a National Parks and Wildlife Service ranger from a cable beneath a hovering helicopter.

The first person to undertake this dubious task was Michael Sharp and perhaps no-one has suffered so much physical pain for Wollemia. The first time he was winched down on the end of a cable Sharp was wearing a borrowed harness. Bill Hollingsworth later described the result: ‘His butt-cheeks were the size of canteloupes by the time we had finished—the harness was a bit tight.’ It was an incredibly painful experience, Sharp recalled, made worse because communications were difficult—he could talk to the pilot but not to Jones, who was directing operations from the cliff using a walkie-talkie.

In September 1995 a chartered helicopter hovered with its nose pointing at the gorge wall. Sharp was offloading gear on the pilot’s side of the aircraft. He was standing with both feet on the skids as the front passenger clambered out— tripping on the chopper’s ‘collective’, which controls the pitch of the blades. It bucked a full three metres into the air and sent Sharp flying. He flew over the ledge, his fall broken by another ledge a few metres down the cliff. If his feet had been straddling the skids the helicopter’s sudden lift could have split him in two. If he had not landed on the ledge the next stop was the floor of the canyon. The chopper was brought back under control and Sharp clambered up, shaken but uninjured. But it is David Crust, another NPWS ranger, who has most often been winched down among the crowns of the pines, armed with a pair of sterilised secateurs, and jiggled like a tea bag. No-one likes authorising these expeditions. If Crust were to become tangled or if there were a sudden gust of wind then the situation could turn disastrous in seconds. There is also the threat posed to the wild trees in the event of a crash. One of the residual problems with trying to collect the seed by helicopter is that its blades, with their downward thrust, shatter the cones because they are fragile when ripe. Up to 50 per cent of cones in early visits were blown open in this way. In one incident the blades of a chartered helicopter actually severed the top of a tree.

During these expeditions Crust takes about half a minute to be winched to the end of the sixty-metre cable. He has a two-way radio in his helmet and gives detailed instructions on exactly where he wants to be positioned. The chopper usually hovers downwind of the trees to minimise the exhaust blowing onto the stand. Crust wears a rucksack on his chest and, because he must remember from which tree he collected material, the inside of the pack is divided into four or five compartments. During the twenty to twenty-five minutes he spends at the end of the cable—his time is limited by the pressure that his harness applies to his crotch—he moves up and down the trees, with the helicopter rising and falling at his command. About eight Wollemi pines can be safely harvested in this way and if Crust can gather a dozen cones on these trips it is considered a success. Throughout he is blasted by downdraft and there is the constant roar of the machine above him. It is an experience that most people would find terrifying but Crust describes it as ‘challenging’.

David Crust stands alongside the helicopter, hovering above the gorge containing the Wollemi pine.

The tree in the stand that has been subjected to the most attention from seed collectors was named by Wyn Jones and Jan Allen as the Bill Tree—after Bill Hollingsworth, the popular and professional crewman in the NPWS helicopter. Hollingsworth, an American by birth, did much of the early search work with Jones. To other researchers the tree is known as Tree One or King Billy—a somewhat confusing name as there is a Tasmanian conifer species called a King Billy pine—because it is the biggest and grandest of the adult Wollemia. ‘It is the most multi-branched tree,’ John Benson told me. ‘The others are basically poles, and King Billy is producing a lot of cones.’

At around forty metres tall King Billy is the tree that most prominently sticks out above the canopy of the rainforest. A tree is a platform to get chlorophyll to the light and to out-compete other trees in the vicinity. ‘Sometimes a tree will never get to the canopy,’ Benson observed. ‘You can be looking at a tree that is maybe decades old but it may only look a few years old. When they get to the canopy as King Billy has they power on, that’s when they have really got the photosynthesis going, that’s when they’re producing food, that’s when they can put starch on their roots. That’s when they can really start building bulk. Once you get above the canopy it is like going to the gym and doing weights.’

Another person who has played a key part in the story of propagating the pines is senior horticulturist Graeme Errington, who was employed at the time at the Mount Annan Botanic Gardens. He visited the trees in the wild soon after their discovery, and his description of his first encounter with Wollemia in February 1995 is vivid.

‘Below the canopy it is quiet. The light is dim. Lichens on the trunks of coachwoods appear to glow in the failing light,’ Errington wrote in his diary. ‘Sassafras, coachwoods and lilly pillys support water vines with stems as thick as my forearm. Soft tree ferns and king ferns line the creek which flows through the population of Wollemi pines. Close to the trees the occasional odd-looking leaf branch lies in the water. A diamond python, which has fallen into the crown of a tree fern, awaits the sun so it can warm its blood and seek higher ground. A break in the coachwoods reveals a single Wollemi in the middle of the creekline.’

The Mount Annan Gardens is a few kilometres off the freeway that carves through the countryside between Sydney and Melbourne, and is surrounded by the suburban sprawl of south-western Sydney. The headquarters of the effort to cultivate Wollemia is a line of buildings in one corner of the gardens that is off limits to the public. Pines grown at Mount Annan are all unique in their shape—some are tall and spindly, others spectacularly bushy. They grow in pots in neat rows in two separate areas. One is outside exposed to the elements, with the only protection from the weather being a huge secure steel wall and a roof of mesh and shadecloth. Others grow in humid glasshouse conditions with a suite of other endangered Australian plants. Even here, among other rare species struggling to survive in the wild, the Wollemi pines look out of place. ‘It’s got an antique look,’ Offord told me. ‘I would describe their growth, at least in cultivation, as very fast and loose. They grow quite fast and they have a very loose arrangement of dormant buds and these buds are very easily stimulated. It could be an adaptation to living in a deep, dark canyon that it is able to take advantage of any breaks in the canopy. It’s almost a plastic plant. It might even be good in bonsai because it’s very malleable—you can change the shape of it quite easily. It’s very responsive to any sort of pruning and it is very responsive to light.’

Cathy Offord knows the history of every Wollemi pine in her care at Mount Annan—from which tree they were propagated and whether they were grown from a seed or a cutting.

Soil tests conducted in the canyon soon after the discovery showed that it was highly acidic. Its pH value is as low as 3.5 in some places, where most soils are about pH 5. Every time you go down a notch on the pH scale it’s ten times stronger and at 3.5 the soil almost has the capacity to erode anything growing in it. ‘It’s getting pretty close to meaning that a lot of species wouldn’t survive there,’ Offord said.

The attrition rate for seed in the canyon is high. Much of it is eaten on the trees by birds and by native rats and other creatures once it falls to the ground. About 20 per cent of seed is consumed by fungi. Wollemi rainforests are so sodden that at times water can be squeezed out of every living and dead thing in the base of the gorges. Many pieces of timber have bracket fungi bursting through their surfaces, looking like neatly stacked plates from a dollhouse dinner set—in every imaginable colour. Without the infinite variety of mushrooms and their relatives the canyons would long ago have been choked to the brim with unconsumed vegetation. I have camped in parts of Wollemi where there have been dozens of thumbnail-sized, brilliant red mushrooms poking through the mulch in a miniature forest of their own.

‘There isn’t a lot of soil there,’ Offord said. ‘The plants are growing into the fissures in the rock and probably tapping into a deeper alluvium.’ She and her team were also surprised by the way that the pines thrive when they are removed from the canyons. They grow more strongly and far more bushy in cultivation than in the wild, probably because in captivity they are drenched with light. Once in propagation their survival rate is higher than the average native plant. Offord told me the mortality rate of the average Australian plant in a nursery is around 5 per cent but for Wollemia seedlings it is almost zero. In the greenhouse Offord is running an experiment to try and duplicate conditions in the canyon. A collection of about twenty pines is being grown in 10 per cent ambient light and low pH. They are dwarfs compared to their unrestrained neighbours basking in the sunshine. The experiment shows that the canyon provides sub-optimal conditions for the trees. The Wollemi wilderness has provided the trees with a haven for millennia, but only just.

Offord and her team have gathered together as much wild reproductive material as possible, from many stages of maturity, and have learnt that the months of October and November—the southern hemisphere spring—are one of the busiest and most visually dramatic times in the Wollemi pine’s year. Every Wollemia has both male—long thin pollen cones— and female—spherical seed-cones—reproductive organs. If the Wollemi pine is similar to other members of Araucariaceae it is possible that the entire process from pollination to sexual maturity may take over half a century in the wild.

Around October the unusually large pollen cones, the size of a man’s little finger, release their clouds of minute grains. The millions of particles exploding from the cone resemble a spray from a can of insecticide. If these pollen grains do not land on a female cone and fertilise a seed then they cannot produce a new tree. The odds that pollen and seed will actually meet are extremely low. It is only for a few weeks, maybe even just a few days, that the immature female cones are open and receptive to the pollen grains. The pollen is completely at the whim of breezes, which at the bottom of the canyon are either non-existent or highly unpredictable. For every pollen grain which flukes a landing upon a receptive female cone, millions will fall onto the forest floor where they will be destroyed by the soil’s high acidity. Others will drop in the creek or make their way into swamps downstream. In these swamps the Wollemi grains may be buried in just the right conditions that will one day allow them to be found as fossils, in the same way that its ancestor Dilwynites has been found.

Offord and her colleagues estimate that the twenty-three adult Wollemi pines found by David Noble produce about 150 female cones per year and these cones set between 3000 and 4000 viable seeds (another 30,000 to 40,000 non-viable seeds are grown). Every pollen cone—if it is similar to other members of the family Araucariaceae—produces about 10 million pollen grains. This means that of the billions upon billions of pollen grains produced, a comparative handful get to fertilise a female seed.

The proportion of unviable seed has baffled Offord. A strategy that trees employ to limit further inbreeding may, however, provide the answer. Since each Wollemia has cones of both sexes it is likely that when a male cone releases its pollen the female cone on that tree stays closed. In an inbred population, Offord speculated, the females may have gotten out of sync with the male cones. In other words it is possible that many of the grove’s male cones are releasing their pollen when the female cones on neighbouring trees are not receptive. This is the equivalent of the boys thinking the school dance was on Thursday when the girls are dressed up to dance on Friday.

Sex the Wollemi way is a patient and delicate process. No-one is sure yet of the exact process but, if it is similar to its relatives, the seed takes between sixteen and nineteen months to mature from the moment a single pollen grain is received by the exterior of a single ovule. Around eight months after pollination a sprout will have grown from the pollen grain towards the interior of the seed ovule. When the pollen sprout reaches its destination a few millimetres away, the seed is finally fertilised. About ten months after that the seeds will be ripe, dropping between January and June. At the time the seeds are ripe their cones turn from green to brown and the branches holding them often drop off. There are approximately 250 to 300 seeds packed into each cone but only 5 to 10 per cent are pollinated and fertilised and therefore viable. The remaining 90 per cent of all Wollemi pine seeds are good for nothing but decoration.

A viable seed is instantly recognisable—it looks and feels as though it has a sunflower seed enclosed inside. These then germinate in the leaf litter with two little pre-leaves, which are very common in most plants. These pre-leaves look nothing like Wollemi pine leaves but they contain chlorophyll—the chemical crucial to the energy-producing reaction called photosynthesis. The seeds can take up to a year to germinate and this has proven to be a tortuous time-trial for Offord and her team. During one visit I made to Mount Annan, Offord’s colleague Patricia Meagher produced a tiny white dish containing a seed delicately resting on a bed of cotton wool, like a diamond protected by velvet. Out of the seed a two-centimetre-long lime-green root had emerged. This is the moment when a Wollemi pine is born. The two-centimetre shoot had taken a mere twenty-four hours to grow—in the context of an eighteen-month gestation it seemed to me an explosion of life.

‘That’s amazingly fast,’ I said.

Offord and Meagher both responded instantly. ‘It has sat there for six months.’

One theory being tested is that the seed requires chilling to germinate. ‘Time in the fridge,’ Offord says, ‘can accelerate germination to less than a month.’ This ensures that the seed germinates after winter when temperatures begin to rise. The downside to this climatic strategy, however, is that the seed is more likely to rot or be eaten.

A few weeks later that little newly sprouted Wollemia develops a very distinctive kink in its trunk near the base—a bit like a sudden twist in the road. The kink settles into the ground as a kind of buried root. Every Wollemi pine seedling develops this kink. By the end of its first year a Wollemi pine in cultivation stands up to twenty-five centimetres tall and has as many as seventeen branches. By three years of age a cultivated Wollemi pine can be over two metres tall and have more than seventy branches.

By April 1995 Offord and her team had also succeeded in cloning the pines. This was done in two ways: the first was a traditional method of taking cuttings and growing roots on them. The second was by tissue culture. Around 500 tiny fragments of Wollemia were put into test tubes in special gel. Hormones were added to make various parts of the tree grow and twenty tiny Wollemi pine clones were created, though all were incapable of growing into actual trees. Tissue culture is a means to grow many trees rapidly if there is no other alternative and, because it is tissue-specific, finding the perfect recipe of growth regulators for each part of the tree—roots, trunk, etc—is time-consuming. But members of Araucariaceae family are tricky subjects for this means of propagation and Offord decided the best way to grow trees was from cuttings. To do this vertical shoots need to be obtained to produce trees that grow properly. Offord’s team have also gone a step further and propagated the side-growing branches of Wollemia to produce a conifer that grows along the ground.

In April 1995 the prehistoric Wollemi pine was successfully propagated. This image of the ‘dinosaur tree’ cloned in a test tube was published on the front page of the Sydney Morning Herald.

In the same month the Wollemi story was to take a bizarre new twist which would have major consequences not only for Offord but for all of the scientists who had begun studying the pines.