The New Nature Read online

  Velvety peppercress (Lepidium hyssopifolium) is by far the most intriguing ‘endangered weed’ I’ve come across. It was considered long extinct in Victoria after no sightings since 1893, and was only known to exist at a few sites in Tasmania. But in 1984 Neville Scarlett was botanising along the Melbourne–Sydney railway line near Beveridge when he came to a South American pepper tree by a fence. Underneath were six rabbit-chewed shrubs. Velvety peppercress was back.

  Simon Cropper was visiting his parents near Bolwarrah, Victoria, two years later when he found his father by the garden shed trampling a shrub and forcing it under a mower. ‘It was purely by coincidence that I discovered it,’ Simon said of his peppercress discovery. Twenty or more plants grew along the side of the shed among weeds. ‘I looked a bit further afield and it was occupying most of the roadsides within cooee.’ Simon found 400 peppercresses all up, with the biggest throng, 250 strong, occupying a weedy horse paddock on the ruins of a bulldozed school. None of the cresses was anywhere near a forest; there isn’t any forest around Bolwarrah.

  Simon lobbied for the school paddock to be made a nature reserve. ‘We then asked them to remove the horse and they did that.’ But the horse had been keeping down rank grasses without harming the peppercresses. The weeds could now take over. ‘Reintroducing horses is probably the most sensible thing to do,’ Simon told me in 2000, but by then it was too late. The government, by not watching over the site, lost all 250 endangered plants, the world’s largest colony of Lepidium hyssopifolium. But some plants growing outside the reserve under cypress trees cast seed into an empty paddock, and the population swelled to 590.

  Neville’s six plants near Beveridge also vanished, swallowed up by weeds and their substrate torn up for a Telstra fibre-optic cable (despite instructions to the contractors to steer clear of the South American pepper tree). But Neville had gathered some seed, and their progeny survive at La Trobe University.

  More peppercresses turned up in 1991, at Trentham, where someone called Kale Dormouse found six plants in the main street huddled under a Perspex awning between the road and the footpath. Twenty more were loitering around the toilet behind the scout hall. Others stood under Monterey cypresses above a road cutting. No more of these plants have been found in Victoria.

  Velvety peppercress is something to wonder about: a nationally endangered plant that grows in weedy places – roadsides, lawns, paddocks – among foreign weeds. When Neville Scarlett grew it in Melbourne as a conservation project, it spread. He now has endangered plants sprouting in cracks on his footpath. The council sprays them each year but they return from seed, creeping further along his pavement.

  To see this most curious of plants, I went to the historic town of Oatlands, Tasmania, to a park full of radiata pines and Monterey cypresses by a semi-artificial lake. Even before I locked the car, I could see my quarry in the lawn by the main road, the stems lopped off by a mower. Others were drowning under pine needles or sprouting in the dirt below conifers, which proved to be a prime habitat. They weren’t much to look at – flimsy green things growing like weeds – but I was suitably impressed. I was on my knees in a town founded by Governor Macquarie in 1821, a stone’s throw from a windmill built in 1837, peering at nationally endangered plants growing under American trees. When I later went to Hobart and saw three other rare species growing under exotic conifers I came away with altered eyes. I can now look at pine needles in a park and half expect to find rare plants.

  Velvety peppercress survives in twenty-eight places in Tasmania, mostly ‘on roadsides underneath exotic tree species’, said one report, ‘with a substantial minority in the home yards of farms’. It grows under pines beside Pontville’s St Matthew’s Church, founded in 1867, and beside the nearby oval – though Pontville was cress-less when I looked. Near Ross it sprouts around an abandoned sandstone house. This cress (and related L. pseudotasmanicum) went weedy long ago, with naturalist Ronald Gunn describing them in 1844 as ‘a very common weed about Penquite growing about the roots of plants, hedges, fences, etc. – and amongst rocks in the wilder places’. Only in one place is this plant still tied to a natural habitat. Near Tunbridge, Tasmania, it grows in woodland at the feet of gums and wattles, preferring the southern and eastern sides of trees.

  This story gets stranger. Velvety peppercress has become a foreign weed, sprouting in New Zealand along roads and railway tracks in Wellington, Christchurch and Dunedin, and even colonising the remote Kermadec Islands. (Ironically, the two bell-frogs mentioned earlier also occupy New Zealand, living in farm dams as the descendants of frogs taken over there in the 1860s.) Peppercress probably went abroad on sheep fleeces. Its seeds travel well in wool, five of our threatened Lepidium species having turned up in Europe or New Zealand. (One of them – Lepidium peregrinum – thought until recently to be extinct, is now known from two sites, one of them a garden west of Brisbane.)

  So what does all this mean? Cattle and sheep (but not horses) dote on peppercresses, and they exterminated this plant over most of its range. It can’t abide thick grass, growing instead where the earth is bare. Near Tunbridge it grows in the suppression zones below native trees – perhaps prime habitat in the past. Grasses fare poorly in such places because tree roots steal moisture and leaves throw shade. The mystery is why zones under exotic conifers are now preferred. Perhaps eucalypts drop too much litter, which bushfires aren’t removing any more. Fire suppression may be harming this plant, along with foreign weeds that claim bare dirt. In Ronald Gunn’s day it prospered as a weed, but legions of foreign weeds have invaded Tasmania since then. Foreign trees may suit it best because they cast more shade. Velvety peppercress tolerates gloom better than most weeds.

  This is one rare plant we could easily save. Seeds could be cast into vacant allotments and along railway lines. ‘Roadsides provide many opportunities for such introductions,’ noted Jamie Kirkpatrick and Louise Gilfedder in a journal article. ‘So do city parks, cemeteries, large country houses and grassy woodland remnants managed for conservation.’ Jamie planted seed under an exotic oak in Hobart’s Domain, and the cresses thrived until a zealous ranger felled the tree, allowing weeds to take over. Like many cresses, velvety peppercress tastes spicy. I tasted a leaf at Oatlands – the only endangered plant I’ve ever eaten. Could we save this cress by introducing it into our herb gardens?

  Tasmania has another rare plant that’s a very serious weed, at least for farmer David Amos. His plight is to live in one of the few valleys where the tea-tree (Melaleuca pustulata) grows. This cheerful-looking shrub with fluffy yellow flowers is stealing David’s land while he watches. He took me up rough tracks to backblocks where the rare shrubs are merging into stands so thick you can barely squeeze through.

  ‘Our people came out in 1821 and we’ve been grazing sheep ever since,’ he told me. In the old days the tea-tree wasn’t a problem. David’s father paid cutters to clear the land and hack back regrowth, but labour costs more today and the shrub has seized its chance. Tea-tree would not have thrived here like this when the land was still forested. ‘It’s certainly true that when you remove the timber it thickens up,’ David admitted. Sheep don’t like this plant, unlike many rare weeds, instead helping it invade by grazing down competing plants.

  The tea-tree is beyond David’s control. Burning and bulldozing don’t work. ‘If you torch it then you’ll get a whole heap of young ones coming up.’ Melaleuca pustulata only grows in eastern Tasmania around Oyster Bay, mainly in a belt just 25 kilometres long and wide. Only on two farms does it misbehave badly. It’s a protected rare plant and David breaks the law when he harms it. He only found this out on the day of my visit. It’s a tough call: this plant deserves conserving, but not by letting it swallow up a farm.

  I was shown another rare ‘weed’ on the Darling Downs by biologist Owen Foley. It’s Austral cornstalk (Stemmacantha australis), a native thistle long extinct in Victoria and New South Wales, and listed as vulnerable in Queensland. ‘I’ve been wondering about Stemmacanth
a ever since I first saw it,’ Owen said. ‘It’s a failure as a weed yet appears to have most of the qualifications. What is missing?’ He is puzzled because it should be thriving. Three of the colonies we saw were on roadsides beside paddocks, largely within remnant strips of native grassland but also among weeds. With pink petals crowning artichoke-like globes, the plants were gorgeous to behold, but when you’ve seen them too often in the company of turnip weed and African grasses they end up looking like foreign weeds themselves. Two of the plants, growing on a dirt road, were bent over by passing cars yet flowering happily. ‘You can’t think of this plant as a delicate, sensitive little thing that needs its hand held,’ Owen said. It even likes to grow in piles of gravel (‘blue metal’) dumped for construction work.

  But although cornstalk does well enough along verges, it doesn’t survive among cows, and that is its problem. The fourth site we saw was the corner of a field that was otherwise ploughed to grain. ‘It doesn’t look good,’ Owen said when we parked. ‘It’s been grazed.’ When Owen found this important site two years ago, it hadn’t been grazed in ages. The ground that day was littered with dung. ‘This site had all the grasses of the Darling Downs, thick and beautifully intact.’ We did find some cornstalk seedlings but all the older plants had gone – inside cows. ‘Here is a good picture for you,’ Owen said, crouched over a dried cowpat with three young cornstalks pushing through. Like peppercresses, cornstalks are bare-ground colonists. Intermittent grazing helps them by removing some grass, but they disappear when grazing is constant. The verges on which they now survive are probably grazed every so often during droughts. We left the paddock that day pondering its future. No-one has told the farmer that he owns one of the best remnants of grassland in southern Queensland. Probably no-one will. This is rural Australia. We don’t want him firing up his tractor and ploughing the past to dust.

  When I work as a consultant, I often find rare plants in strange places. I once found an attenuate wattle (Acacia attenuata), rated vulnerable, blooming gloriously near the edge of Caloundra’s old rubbish tip on bulldozed land ringed by weeds. I’ve mapped out colonies of eprapah wattle (Acacia perangusta) – also vulnerable – lining roads and paddocks but shunning intact bushland. Once I had to reverse over dozens of rare acoma daisies (Acomis acoma) to get my car out of a bush track in the mountains; they were sprouting along the tracks and nowhere else. It’s a perverse fact that many rare plants will sprout along woodland edges in the wake of bush-bashing bulldozers.

  Rare frogs and plants acting oddly – what else? How about a marsupial? The eastern barred bandicoot, a long-snouted, ground-shuffling mammal, lived on the grassy plains of western Victoria, but by 1976 foxes and farmers had nearly snuffed it out. Its last mainland colony was centred on the town of Hamilton. When John Seebeck began working there in the 1970s, bandicoots were cavorting through gardens, darting across roads, and clawing up the local footy field and cemetery. ‘It was just part of the local lifestyle that you had bandicoots in the garden,’ he said. ‘They would nest in piles of garden refuse; they would nest under outhouses, under houses, in garden beds, under bushes.’ John can’t say why they hung on there and nowhere else. ‘There really isn’t anything much in the way of naturalness about Hamilton,’ he said. ‘It’s everything a country town is, from a built-up shopping centre to light industrial, parks, gardens, and so on.’ Thickets of prickly exotic gorse around the outskirts proved an important refuge. So did the municipal tip. A survey done there found bandicoots nesting against ‘wire and metal debris, cement culverts, railway sleepers, car tyres, and galvanised-iron guttering’.

  When the townsfolk found they were harbouring an endangered species, opinions polarised. ‘There were some members of the community who were quite happy with us trapping bandicoots in their backyard,’ John said. ‘Others insisted they were just rubbish and should be got rid of . . . People would take our traps out from where we’d set them, run over them in a motor car and put them back. Or use them as footballs. We had people cut fences, cut chains and open gates. We had cats thrown over fences where the bandicoots were. We put up signs saying “No mowing beyond this point” and tractor operators would come and pull out the signs and mow beyond them.’

  John persevered with his work and seven new bandicoot colonies were founded in Victoria. But urban habits die hard. At one reserve, a property near Hamilton, bandicoots come to the door at night to pluck moths from the fly screen. At the National Trust property Moomong, near Skipton, bandicoots found refuge in the homestead gardens when drought struck. Fertilised gardens furnish more insects than natural woodlands, especially during drought.

  Hamilton’s remaining bandicoots are faring poorly. John Seebeek expects them to vanish soon. He blames certain urban trends – more cars and more houses on vacant land. ‘At Hamilton they’re also very heavily into tidy town-ness,’ he said. ‘So there’s not the ready availability of easy cover that there was.’ Gardens are becoming neater and the fringes of town less weedy. ‘Gorse was the principal environmental weed and very good for the bandicoots,’ he explained. ‘One of our small study populations of bandicoots was disrupted when the paddock ownership changed hands. The new owner was very conscientious and thought, I’ve got to get rid of this, and he did. He buggered up the bandicoots. That patch of gorse was home to five or six bandicoots and had been for quite a long time.’

  Tasmania also has barred bandicoots and there, with no foxes, they are faring much better. But their habits have nonetheless changed. In their original stronghold – the grassy woodlands of the Midlands – they are now very rare. A few colonies linger on among belts of prickly weeds, one of them in Oatlands. It amazes me that this very old town can boast both an endangered peppercress and a rare marsupial. The bandicoots nest under gorse around the outskirts of the town. Tasmania once carried a mantle of thick forest around its edges and grassy woodland (bandicoot land) in the middle. The Midlands are now bleating sheep fields and the bandicoots have gone north and south, moving in wherever farms replaced forest. Today their stronghold is the Huon Valley, south of Hobart.

  On some northern farms they are now suffering from clearing of gorse and blackberry as farmers convert from beef cattle to dairy cattle. A fungus brought in to kill blackberries is adding to their woes. In Hobart’s western suburbs they live in gardens a block or two from bushland. I have watched one at night scratching up a lawn near a wandering dog. Most barred bandicoots now live among weeds on farms, or among shrubs in gardens, and exotic earthworms fill their bellies. They showed a fondness for gardens long ago: Ronald Gunn, after whom they are named (as Perameles gunnii), complained that his garden near Launceston ‘suffered severely’ from them digging up his crocus bulbs and whole rows of ixia.

  Where else do rare things live? How about a wheat field? No-one in their wildest dreams would think of looking for a new animal among wheat, yet in 1984 an entirely new rodent, yet to be named even today, was found molesting crops in central Queensland. The rodents were chewing through wheat stalks for the moisture, destroying up to 90 per cent of the stalks. They swarmed into fields of sunflower, maize and sorghum, eating growing seeds. Crop losses ran into millions of dollars. The rodents also invaded cotton fields and made cosy burrows lined with cotton bolls. Farmers countered by laying hundreds of tonnes of baited grain. The rat plague abated, and in recent years few have been seen. National park rangers have trapped these rodents from grassy roadsides near crops, but no substantial population has been found in a natural setting. Crops have replaced their original habitat.

  Farms offer salvation to many in need. The star finch, a dainty little bird with a bright red head and starlike spots, was discovered by John Gould in New South Wales in about 1839. It’s now all but extinct south of Townsville, for reasons that remain unclear. In central Queensland this finch is now ‘critically endangered’, a recent report noting that ‘the three most recent sightings have been in cleared, or even suburban, settings’. But in Western Australia star finches are
doing well by harvesting seeds of weeds in well-watered towns and irrigated fields. Cows, by grazing down seedheads in woodlands, force them to rely on urban, roadside and cropland weeds. I have seen these cute birds hopping about at a roadside picnic spot near Roebourne, harvesting African buffel grass seeds.

  A common assumption made today is that rare species hide away in remote places – out in deserts or up on rainforest-clad peaks, for example. This is a message sold by TV shows and it makes sense. People cause extinctions, so rare species should hide away from us. But in truth there are endangered black cockatoos in Perth parks, rare bats in mines, threatened ringtail possums in gardens (in Busselton, WA), rare plants in quarries, and so forth. The wealth of examples suggests that our image of nature may need refining. Australia has one of the worst extinction records on earth (we are ranked fifth by the World Conservation Union) and we need to know what our rare things are doing. Our roll-call of extinctions includes one peppercress (L. drummondii, last seen in 1879), three bandicoots and about ten frogs. But when ecology reporter Claire Miller wrote in The Age of frogs at Homebush having been ‘locked out of their natural environment when the mangroves and saltmarshes gave way to chemical plants and waste dumping’ she didn’t understand at all; nor, presumably do most people. Bell-frogs can’t abide mangroves and saltmarshes. Rare things often hide away in odd places because the threatening process is often not people themselves but an exotic invader – a fish, a fox or a disease. Cities can offer protection against these.

  The rare things considered so far have been found in contrived environments. Yet even when we turn to something very different, a bird in a remote national park, things are not as they seem. The endangered orange-bellied parrot, numbering about 200, is certainly one of our rarest birds. It’s a pretty green bird with navy blue wings and a smudge of orange below. You won’t find it in quarries or pine trees. In summer it hides away in the remote wilderness of south-west Tasmania, about as far from people as you can go, where it feeds on the buttongrass (Gymnoschoenus sphaerocephalus) moors.