European brambles cannot survive in subtropical rainforest, thank goodness. In their stead, we have to struggle with descendants of Suttor’s oranges. We call them ‘bush lemons’. They are probably versions of the ‘rough lemon’ or Citrus jambhiri that was used extensively for more than a hundred years as the rootstock for Australian citrus, especially in Queensland. Citrus jambhiri was thought to have originated as a distinct species in the foothills of the Himalayas, but biotechnological data now suggest that it is a hybrid of Citrus limon and an unknown co-parent. Because they are highly sensitive to citrus root rot (Phytophthora citrophora) and to citrus nematodes, rough lemons do best in land where citrus has never been planted before, which means that they do especially well in rainforest.
Given copious rain and rich basalt soil a bush lemon grows into a stout suckering thicket, so well equipped with long sharp spines that the only way to get rid of it is to thread a chain around it, hook it up to a tractor and drag it bodily out of the ground. Every fragment of root left behind will send up an aggressively spiny new shoot. The fruits, often huge and knobby, are jammed with seeds. Cockatoos, corellas and other fruit-eating birds besiege the bush lemon trees when they are in fruit, so that the seeds are scattered far and wide. Often as I tramp in the most inaccessible parts of the forest, a citrus twig will catch at my leg and my eyes will suddenly water as the bruised leaves emit their piercingly acrid smell, vaguely recognisable as an intensification of the bridal scent of the cultivated varieties. Then I open my scrip, take out my bright yellow plague tape and brave the stout spines to tie a fluttering length around a branch. Next time the workforce comes by with the herbicide and the brush hooks it will be put to death. Except for one tree, that I have marked three times and still it survives. It bears a thin-skinned fruit rather like a clementine, brim-full of sweet juice much appreciated by the workers. So far the young’uns have refused to kill it, and simply assure me that no fruit is ever left for the birds and that all the seeds end up in the garbage.
There are native citrus species that could have been developed to provide the infant colony with its necessary Vitamin C, but nobody was looking for them. The first was not discovered until Walter Hill came across it ‘in nemoribus circum sinum Moreton Bay’ in 1857 and called it ‘Citrus cataphracta’. Because its fruits were small, when Mueller came to revise Hill’s work in 1858 he called it Microcitrus australiasica (sic), and published the new name in his Fragmenta (2:26). He should have known better; a citrus is a citrus whether it is small or large. He made a similar mistake in dubbing the desert citrus ‘Eremocitrus’. Both fake genera have finally bitten the dust. Eremocitrus glauca is now Citrus glauca, while the rainforest Finger Lime is Citrus australasica (Mabberley, 1998, 4). The native citrus that grows along Cave Creek produces an abundance of fruit of an irregular fusiform shape that might suggest a swollen finger, on some trees dark green, on others almost black and on others red or translucent yellow. A red form found at nearby Tamborine Mountain in 1892 was identified by F. M. Bailey as Microcitrus australasica var. sanguinea, but the variability demonstrated by those at Cave Creek suggests that the varieties are anything but distinct. The flesh, whether palest green-white, blush-pink or red, is formed of tiny faceted vesicles much more solid than the vesicles in oranges or lemons. It takes a strenuous tongue to pop one against the roof of the mouth, but the taste is worth it.
I use Finger Limes to make an Australian version of the Brazilian caipirinha. After the seeds have been removed for propagation, I pound the whole fruit, skin and all, in a mortar, then add cane syrup and a measure of white rum, leave it to steep for five minutes, and then pour the lot over cracked ice. In the wild Citrus australasica grows leggy and straggling in deep shade. It responds well to shaping at first, growing into a handsome buffle-headed tree, but the tighter vegetation soon develops fungal diseases, the overcrowded head dies back and the tree reverts to its old habit. Like many citrus the Finger Lime has fruit and flowers all the year round, and a clean and pleasant scent. There should be one in every frost-free garden in Australia, but you are much more likely to find nurserymen offering any of literally thousands of exotic citrus cultivars – bergamots, calamondins, clementines, mandarins, orangelos, satsumas, tangerines, tangors, tangelos, Buddha’s hands.
Part of the job description of a nineteenth-century government botanist was to search for new cash crops; appointed Queensland Colonial Botanist in 1881, F. M. Bailey played his part by sending examples of Australian citrus to Kew for the Economic Botany Collection in 1895. Then the species of native citrus were thought to be three: the finger lime, Citrus australasica, the round lime, Citrus australis, and Citrus inodora, the Russell River lime, discovered by Bailey in 1889 and described by him as ‘resembling a small Lisbon lemon with a flavour like that of West Indian Lime’. Besides examples of all three preserved in spirits, now kept in the Joseph Banks Building at Kew, there is a small wooden box of dried Finger Limes. Alas for Bailey, another botanist has horned in on his Citrus inodora; a subspecies has been reclassified as a species of its own, Citrus maidenii, in honour of J. H. Maiden. It’s enough to make Bailey regret he didn’t call his lime ‘Citrus baileyii’ when he had the chance. Another rainforest lime has now turned up on the Cape York peninsula, Citrus garrowayae, Mount White Lime. Those who, like Queensland government botanist C. T. White, cannot believe that Bailey named the species for Mrs Garroway rather than her husband, often render the name incorrectly as Citrus garrowayi.
For a hundred years nothing was done about exploiting the Australian citrus species, although early settlers did use them for marmalades. In the 1960s there was some investigation of their possible usefulness as rootstocks for exotic species and possibly breeding desirable characteristics into new cultivars, but no one attempted selective breeding within the species themselves. In the 1990s, with a new awareness of native food sources, exploration of the potential of the Australian citrus species suddenly took off. By 2005 six cultivars had been registered with the Australian Cultivar Registration authority: ‘Alstonville’, ‘Jali Red’, ‘Judy’s Everbearing’, ‘Mia Rose’, ‘Purple Viola’ and ‘Rainforest Pearl’. At CCRRS we concentrate on propagating our wild stock, so that it will still be there when the cultivars conk out. Meanwhile both the Mount White Lime and the Russell River Lime have been brought to the verge of extinction.
Most of the early settlers in the Numinbah Valley had a go at growing exotic citrus; Carl Lentz’s experience was fairly typical:
The citrus fruit trees grew splendidly in those times, but a disease got into them just as they came into bearing. I wrote to Mr Benson the government fruit expert and he came and prescribed a remedy. I had to spray the trees with boiled Stockholm tar, rosin and caustic soda. It killed scale disease alright but then they got fungus growing on the roots and there was no hope for them.
When apples, pears, peaches, cherries, mulberries, apricots and plums failed to naturalise and quickly succumbed to pests and infestations of all kinds, the settlers tried avocados, passionfruit, guavas, pomelos, loquats, mangoes, papayas, tamarillos, kiwi fruit, custard apples, durians, persimmons, sapodillas, grenadillas, breadfruit, jakfruit, abius, rambutans, Panama cherries, lychees, mangosteens, carambolas, nashi pears, longans, acerolas, jaboticabas, grumichamas, Malabar chestnuts, pecans, pomegranates, casimiroas, okra, feijoa, and so forth. Nobody knows or apparently cares which of these fruits might colonise the wilderness. Every day we come across self-seeded mulberries, guavas, loquats and tamarillos growing under the canopy. For years an acre of pasture has been covered by the spread limbs of a single vast passionfruit vine. None of these has had as devastating an impact as a fruit that cannot seed itself at all, the banana.
Commercial bananas are sterile hybrids that were first bred millennia ago by crossing Musa acuminata with M. balbisiana. They therefore cannot naturalise and cannot become weeds. It was the clearing of tracts of montane subtropical rainforest that had previously been spared because they were too steep for cattl
e, to make space for bananas, that scarred the highest forest slopes for ever. All around the Mount Warning caldera and the Numinbah Valley, what were once luxuriantly forested mountainsides are now great tracts of Lantana, the only memorial to the heroic effort put in by struggling farmers who thought that the new cash crop would finally free them from the tyranny of the banks.
The banana was brought to Australia with the First Fleet in 1787; the Sydney Gazette assured its readers in 1809 ‘that the banana can be reared in the Colony, there being now two trees, each bearing a bunch whereon are two to three dozen nearly ripe, in the garden of a Gentleman a few miles from Sydney . . .’ (The banana is, of course, not a tree, but a herb.) Commercial banana growing was established as early as 1858 when George Bennett could say:
The Banana-tree grows luxuriantly in New South Wales, more particularly at Broken Bay, extending to the north as far as Moreton Bay; from the latter district large supplies are sent, together with Pine-apples, to the markets of Sydney and Melbourne . . . Many persons in New South Wales acquire a good income by growing Bananas and Pine-apples as a commercial speculation . . .’ (Bennett, 331)
We can only wonder which bananas were being grown on a commercial scale in the 1850s. The usual account of commercial banana growing in New South Wales credits ‘Herman Reich’ with bringing Dwarf Cavendish cultivars to Coffs Harbour in 1891. Within a few years banana growing had spread north to Woolgoolga and ultimately to the Tweed. As nothing beyond the name is known about Herman Reich, and bananas were grown in the colony long before he got into the act, I have begun to wonder whether he ever existed.
It was not until the 1920s that the Western world woke up to the food potential of the banana which had long been a staple of the diet of poorer people elsewhere in the world. Huge tracts of land in the tropics were taken up for commercial banana production. Eventually Australia too climbed onto the banana bandwagon, but it was already too late.
The pioneer of bananas in the Numinbah Valley was Jack Morgan, who in the late Twenties acquired two properties above CCRRS and cleared them for planting. In December 1928 Morgan, with Fred Lentz, another of the succession of owners of CCRRS, and Alex Ferndale, travelled to Goomboorian near Gympie to fetch banana suckers. Morgan planted 2,000 of them on his portions before cunningly selling out. All over Numinbah, on both sides of the border, people were clearing, buying, selling and renting land to grow bananas. In 1931 Fred Lentz, who may have learnt a thing or two from Jack Morgan, leased his land to Harold Smith, Bert Harrison and Tom Stephens who, with almost unimaginable effort, cleared and burnt off fifteen steeply sloping west-facing hectares of the CCRRS forest and planted bananas. That winter the plants were badly frosted (Hall et al., 97). One can only wonder why, before crippling themselves with such backbreaking toil, the planters did not consider the chances of such an outcome. At Cave Creek we calculate about ten nights of frost a year; perhaps the west-facing slopes of the property were chosen because it was thought that frost would drain down them, but if frost meets a thirty-metre wall of rainforest it will pool and stay. On a clear winter’s day the banana plants on such a west-facing slope would remain frozen until the sun came over the scarp late in the morning and hit them like an acetylene torch.
The Great Depression had bitten deep when, in 1932, a plan was launched to subdivide the properties in the Upper Nerang and lease them to unemployed men for banana growing. For years arguments for and against the scheme raged in the correspondence columns of the local newspapers. Meanwhile the Australian banana-growing industry was collapsing because the frenzy for producing the new cash crop had produced the inevitable glut. The price of bananas tumbled even before the government entered into a deal with the Fijian government allowing cheaper Fijian bananas onto the Australian market. By 1935 most of the Numinbah banana plantations were abandoned and many of the people who had arrived during the banana boom had left the valley. That year Fred Lentz sent off a consignment of sixty cases – and got back a postal note for one shilling and sixpence, which was nowhere near enough to cover the cost of cases and cartage (Hall et al., 97).
Nevertheless banana growing continued off and on in the Numinbah Valley until the Seventies. Elsewhere in south-east Queensland and north-eastern New South Wales people who still grow bananas are reduced to selling their crop on roadside stalls, which are among the few places where one can find delicious Lady Finger bananas; the supermarkets are interested only in the much larger and starchier Cavendish varieties. Even when a cyclone wiped out the entire north Queensland banana crop, the supermarkets could not turn around and give the southern growers their first profitable year in a generation. All that remains of the short disastrous career of CCRRS as a banana plantation is fifteen hectares of steep Lantana scrub and, somewhere in the middle of it, the footings of the flying fox by which the banana boxes were sent on a cable suspended above Cave Creek towards the Nerang–Murwillumbah Road. A few weeks after one of our periodic summer deluges, we found that a banana plant had washed up on the creek bank, hoisted itself upright, spread its roots and set fruit. It was more than we could do to put such a valiant survivor through the mulcher but, now that it has become a stout thicket of ragged fronds twenty feet high, its days are numbered.
Nuts
‘Are these Macadamia trees?’ asked Jenny. We were standing beneath a knoll in rolling country at Umawera, north of Hokianga Harbour on the west coast of the North Island of New Zealand, on a chunk of her native land that Jenny had just acquired. I had come to see her in her green domain, away from the pressures of her busy life as a professor in Cambridge.
I was also keen to take a look at a different kind of Gondwanan rainforest, only to realise as we drove the length of the North Island that virtually all of the New Zealand rainforest was gone. Jenny took me to Waipoua in Northland, and there I met the greatest of all Gondwanan survivors, the huge Kauri called by the Maori, and therefore by all New Zealanders, Tane Mahuta. This fabulous tree is nearly as big as the Leaning Tower of Pisa, being 51.5 metres high, 13.8 metres round. Waipoua was bought from the Maori in 1876 for £2,000; in 1895 it was dubbed a State Forest Reserve; in 1913 part of it was set aside as a national Kauri forest. In 1952 after decades of popular agitation led by zoologist William Roy McGregor the area was proclaimed a forest sanctuary. Even so the New Zealand government began clear-felling there in the 1960s; by the time this was stopped in 1972, by an incoming Labour government in response to public outcry, a fifth of the forest had been cleared.
Neither Jenny nor I knew when we came to pay homage to Tane Mahuta that a new Kauri-specific fungus infection called Phytophthora taxon Agathis had made its way to Waipoua. PTA was first recognised on an offshore island in 1972; in 2006 it was found on the mainland. The symptoms, yellowing of the foliage, thinning of the canopy, stem girdling of lower branches and gummosis, bleeding of resin from lesions near the foot of the tree, are slow to appear. The only precautions that can be taken are the ones that have not worked in controlling the spread of Phytophthora cinnamomi in Australia. Tane Mahuta was alive when Christ was born; it may not survive for much longer, because in 2006 an advanced case of PTA was found on another Kauri in Waipoua, less than half a kilometre away. A proposal for a 14,000-hectare Kauri National Park is at present under discussion; if it should go through it looks very much as if a substantial part of the park will have to be closed to the public if the Kauri is to survive.
Most of the Kauri in the Northland was felled and replaced by Monterey Pine, which New Zealanders know by its botanical binomial as Pinus radiata. At 2,900 square kilometres the Kaingaroa Forest on the North Island is the largest planted forest in the world. Most of the trees on Jenny’s property were seedlings of P. radiata, often called wilding conifers.
The trees Jenny and I were looking at were buffle-headed with stiff leathery leaves, more or less opposite and mostly stalkless.
‘They are Macadamias, aren’t they?’
‘They look proteaceous but if they’re Macadamias they’re a
bit different from mine.’
‘They’re not natives,’ said Jenny. ‘There are only two proteaceous species in New Zealand, Rewarewa and Toru, and they’re not either of them.’
Rewarewa, Knightia excelsa, is a lovely thing, especially when it is young, with stiff, narrow, bright green, saw-toothed leaves sometimes edged with red, growing in whorls. Its wine-red flowers with projecting styles are typical of the Proteaceae, and they turn into a cluster of cigar-shaped nuts that still carry a long whisker of withered style. The species, which was collected by members of the Endeavour expedition, is supposed to grow all over the North Island, but I didn’t see a single specimen of it in the wild or anywhere else. If I were Jenny I’d be propagating it like mad. Toru, Toronia toru, is a columnar shrub with an open tetramerous flower that smells strongly of honey, rather like our Persoonia. It too should be growing on Jenny’s property, but we didn’t see it. Instead we were looking at fourteen Macadamia lookalikes.
I wasn’t enjoying being at a loss. ‘I’d have said these were cultivars of some kind, but I thought all the cultivars were selected from Macadamia integrifolia, which has leafstalks and entire leaves and cream flowers. The ones at Cave Creek are Macadamia tetraphylla, and these look a bit like them.’
‘How old would you say they are?’
‘They grow slowly. Twenty years, mebbe?’
‘That would figure,’ said Jen. ‘About twenty years ago there was a push to get New Zealanders growing Macadamias. A lot of people got burned, because there was no infrastructure or marketing strategy. I think the trees produced all right but there was no way to sell the crop.’ I found out later that the cultivar of choice was and still is ‘Beaumont’, costly to acquire and to farm because it is a ‘sticker’ and doesn’t release its fruit, which means that it is a variety of M. tetraphylla. Because all NZ cultivars are grafted, none of them looks quite like its ancestor in the understorey of the CCRRS rainforest.