The Tree (12 page)

Tane Mahuta is reckoned to be around 1,500 years old. Yet until 1886, when it was destroyed by fire, there lived another kauri known as Kairaru that was more than 20 meters in girth and was thought to be at least 4,000 years old. Small wonder that the Maoris revered the kauri tree—ranking it second only to the totara, of which more later. They never felled one without a ceremony in which they asked forgiveness—although, as a Maori lawyer remarked to me somewhat wryly, “They must have held an awful lot of ceremonies,” for they used vast quantities of kauri timber for houses, boats, and carving; chewed its gum; and used it for starting fires. They felled whole forests. Fossil kauri gum is still there to be dug up: a form of amber. The Europeans were even more rapacious and reduced the kauri’s range from around three million acres to around 198,000. Now New Zealand is protecting its native trees. To walk through a natural New Zealand forest with its spooky battalions of understory ferns, and with little fantail birds to lead the way, is one of life’s delights—and a very accessible one, since the New Zealanders have built so many easy paths, with wooden bridges to span the protruding roots and raised causeways to avoid crushing the wet places and for the kiwis to pass underneath. (Kiwis, flightless and indeed wingless, prowl by night. They hunt for worms and other invertebrates not by sight, as most birds do, but by scent.)

There are
Agathis
species in Borneo, too, in tropical rain forests; and in New Caledonia there are five species, all endemic. By conifer standards
Agathis
is a fairly recent genus; the oldest date from about 65 million years ago.

The genus
Araucaria,
for which the whole family is named, has nineteen species, of which no fewer than thirteen are endemic to New Caledonia—meaning they occur nowhere else. New Guinea has several
Araucaria,
too, and so does Australia. Well known in Europe and America—though not too far north (except as an unusual houseplant) because it’s tender—is the beautiful Norfolk Island “pine,”
Araucaria heterophylla,
which grows straight as a Christmas tree but with branches that curl up at the ends; it’s much favored in the prestigious gardens of embassies and smart hotels in warm countries the world over. But the araucarias best known to northerners are the only two species that are native to South America. The monkey puzzle tree (a.k.a. Chile pine),
Araucaria araucana,
from Chile and Argentina, was once a favorite in suburban gardens (and is still hanging on there; many are only just coming into their pomp). The leaves of the monkey puzzle are leathery and spiky and cling closely to the stems. Perhaps they do give monkeys pause for thought—but monkeys did not appear in South America until about 30 million years ago, and the genus
Araucaria,
apparently far older than
Agathis,
was around about 120 million years before America had any monkeys at all. Perhaps the monkey puzzle had no thought of monkeys but evolved its daunting leaves to deter dinosaurs. (So, at least, some botanists have speculated. Certainly, trees are incomprehensible until and unless we consider their past.)

The monkey puzzle has poor timber, but the Parana pine (
Araucaria angustifolia
) is much loved by do-it-yourselfers for its lovely variable colors, from smooth creamy white to chestnut brown and rich streaky red, tough but not too tough to work with tools of ordinary steel. The Parana pine grows mainly in Parana, Brazil, and also in Paraguay and Argentina, as a flat-topped tree up to 40 meters high with a straight clear bole around 1.2 meters in diameter. It is sometimes known as Brazilian pine and is Brazil’s chief timber export.

Wollemia,
the third remaining genus of this once great family, is the archetypal relict—to be ranked with the coelacanth, the ancient lobe-finned fish that was found in the ocean depths near Madagascar in the 1930s. For until 1994
Wollemia
was known only from fossils, dating from 120 million years ago. Then a group of thirty or so turned up at the bottom of a canyon in the Blue Mountains of New South Wales, Australia. They were growing alongside flowering trees by a stream. They don’t seem to be holding their own in the wild and must now be actively conserved. Finding
Wollemia
was not quite like finding
Tyrannosaurus rex,
but it is conceptually similar.

Nowadays there are no Araucariaceae in Africa, although the fossils show they were there in the past; or, of course, in Antarctica, where they once abounded; or in the Northern Hemisphere as a whole, though they were once widespread there. Truly they are a relict group, and we should be grateful for the survivors.

T
HE
P
LUM
Y
EW AND
O
THER
E
AST
A
SIANS
:
F
AMILY
C
EPHALOTAXACEAE

Here is another archetypal relict family with only one genus
—Cephalotaxus—
and just eleven species. It grows as an understory tree—a shade lover—in temperate forests on mountains, mixed with flowering trees, from the eastern Himalayas through China, Japan, Taiwan, Thailand, Vietnam, and Malaysia.
Cephalotaxus
trees are vaguely yew-like to look at (and in less sophisticated days were sometimes classed with the yews). They are known to Western gardeners by a variety of names, including “cow’s-tail pine,” because everything with dark green needle leaves tends to be called a “pine” sooner or later, and “plum yew,” because the female cones of
Cephalotaxus
give way to a single, soft-skinned seed that looks roughly like an olive—or an unripe yew “berry.”

C
YPRESSES
, J
UNIPERS
, S
WAMP
C
YPRESSES
,
AND
R
EDWOODS
: F
AMILY
C
UPRESSACEAE

The Cupressaceae is the only conifer family that occurs all over the world, on all continents (except Antarctica) and both hemispheres—it is impossible even to guess whether the family arose in the north (Laurasia) or the south (Gondwana). Cupressaceae also has the most genera of all living families of conifers—thirty—although not the most species (just 133). Yet its relict status shines through, for eighteen of those genera contain only one species. In each of them, the once possibly startling diversity hangs by a thread.

The family Cupressaceae has been extended in recent years. In its earlier form, it included only the cypresses, the junipers, the Australian
Callitris,
and the thujas, which look like cypresses. But botanists had suspected for many a decade that there was no clear distinction between the Cupressaceae and the trees that were then placed in the Taxodiaceae—the swamp cypresses and the redwoods. Their cones are similar in significant details (not least in the way they develop), and the bark of a big cypress—thick, soft, and stringy—is indistinguishable from that of a redwood.

Now it is clear that the old-style Taxodiaceae is not a coherent grouping. Really it’s just a group of genera that look roughly similar because they share primitive features—not because they have any special, close relationship. In fact, the various members of the Taxodiaceae are no more closely related to one another than some of them are to the old-style, narrowly defined Cupressaceae. The newly discovered
Metasequoia
seems particularly close to the cypresses. Thus the traditional Taxodiaceae family may be compared to reptiles or the bryophytes—not a true group (a clade) but a “grade”: a collection of creatures with similar general features. So the old-style Taxodiaceae are now combined with the old-style Cupressaceae to form a new, expanded Cupressaceae family. However, you will still find the traditional name Taxodiaceae on labels in botanic gardens. These things take time to catch up.

The trees of the newly expanded Cupressaceae family live in an extraordinary variety of places. Some, like
Chamaecyparis, Fitzroya, Sequoia,
and
Thuja,
prefer very wet and tall forests on coasts. Others
(Chamaecyparis, Cupressus cashmeriana, Taiwania)
live in monsoon cloud forests high in mountains. Some
(Callitris, Juniperus)
thrive at the edge of deserts. One
(Cupressus dupreziana)
survives right in the heart of the Sahara, where there is virtually no rainfall, drawing its water from a fossil aquifer far beneath the surface. Some junipers live at the edge of the Greenland ice cap, in permanent snow. The various trees in their various habitats are correspondingly various in form: from the very squat, like
Microbiota decussata,
which hugs the ground for survival in the Russian far east, to the giant redwood
(Sequoia sempervirens),
which basks in the mists of coastal California and is the tallest tree of all. The Cupressaceae family also includes some of the world’s oldest living organisms—in the genera
Fitzroya
and
Juniperus.
Like the pines, the species of the cypress-redwood family are generally happy in poor soil—and some grow from crevices in rocks, apparently without soil at all.

The old-style Cupressaceae family included twenty-two genera. Most of them contain only very few species, and some only one.
Callitris
is one of only three genera in the family that contain more than ten species. In fact, it has fifteen, of which thirteen live in Australia (two in Tasmania) and two (inevitably it seems) in New Caledonia. In general,
Callitris
favors upland semiaridity, and grows alongside eucalyptus as “fire climax” species: the kind that thrive when everything else is burned out.
Callitris preissii
(a.k.a.
C. robusta
) finds favor as a garden tree sometimes known as cypress pine.

The sixteen species of
Cupressus
are the “true cypresses.” They span the Northern Hemisphere, happy on temperate, moist coasts, in deserts, or on high mountains. In southwest North America one species extends down into Honduras.
Cupressus dupreziana,
as we have seen, hacks it out in the Sahara. The “classic” cypress of the Mediterranean and the Middle East is
Cupressus sempervirens
(“always living”). Some
Cupressus
species are native to the Himalayas and western China. But in the Mediterranean and Asia in particular it is hard to decide which are truly native, because so many have been moved and replanted since Roman times, or perhaps even earlier.
Calocedrus decurrens,
from western North America, has the nostalgic whiff of school classrooms (at least as they were in my day), for its soft, fine-textured timber furnishes 75 percent of the world’s pencils.

The genus
Cupressus
should probably be extended to include the six species of
Chamaecyparis;
either that, or the two should first be combined and then split up again in new ways. The features that are commonly used to tell the two genera apart—notably, the arrangement of the leaves—do not seem to carry enough weight, when taken with other characters. Species of
Chamaecyparis
grow in North America and eastern Asia as tall trees in temperate mixed or all-coniferous forests, from sea level to the mountains. Best known is the garden favorite
Chamaecyparis lawsoniana,
Lawson’s cypress (a.k.a. “Port Orford cedar”) of southwest Oregon and northwest California. In Britain it is often grown as a hedge. In America (though not in Britain) it is acknowledged as a fine timber tree for furniture, ships, oars, paddles for canoes, and church organs. Leyland cypress (x
Cupressocyparis leylandii
), which grows so fast and casts the shadows that cause so much suburban strife, is a hybrid of
Chamaecyparis nootkatensis
(a.k.a. “Alaska cedar,” originally from the coast of northern California and Alaska) and
Cupressus macrocarpus.
Apparently the hybrid first arose in a garden in Montgomeryshire, on the English-Welsh border, at the end of the nineteenth century. The fact that these two hybridized so readily is another reason for thinking that
Chamaecyparis
and
Cupressus
should not be treated as separate genera. But as a further complication, Aljos Farjon and others have proposed that
Chamaecyparis nootkatensis,
together with a newly discovered conifer from Vietnam, should be placed in a new genus,
Xanthocyparis.

Fitzroya
now contains only one species—the cypress-like
F. cupressoides—
but it’s a great one. It is native to the coast and up into the foothills of the Andes of southern Chile and Argentina (a wonderful place to see trees), and given time, it becomes massive. But it needs a great deal of time: the oldest living
Fitzroya
specimens that can be aged are at least 3,600 years old. Many of the oldest trees have been seriously mutilated by time. Lightning has split their protective bark, insects have chewed the wood within, fungus has rotted it away, and birds have probed for insects and made holes for nests, and now there is nothing left of the tree’s interior. The bark and the sheath of living tissue that lies within the bark are left standing like a monk’s habit, but with no one inside. When a tree has been hollowed out like this we may conclude that it is very, very ancient, but there is no way to judge its age precisely. The evidence is contained in the wood, and the wood is all gone. Sometimes
Fitzroya
grows with its own kind, in groves, and sometimes intermingled with the southern beech,
Nothofagus.

Juniperus
is the biggest genus of the Cupressaceae: its fifty-three species account for nearly 40 percent of the whole family. Apparently (like some groups of pines), the junipers have radiated to form many new species in (geologically) recent times. Some live to several thousand years. Between them they span the Northern Hemisphere—and
J. procera
is found south of the equator in eastern and southern tropical Africa. They seem to tolerate almost anything, from subarctic tundra to semidesert, taking all forms, from ground-hugging shrubs to tall trees. Virtually all are drought-resistant. On mountains, some junipers grow to the topmost limit of the treeline.
J. brevifolia
is endemic to the Azores—and is the only conifer established on any midoceanic volcanic island. Its juicy “berries” must have been taken there by birds.
J. communis
is the most widespread conifer species of all, and has even put in an appearance as one of Britain’s three (possible) native conifers.
Juniperus
as defined here includes
Sabina,
a name that still features in many texts and may turn up on botanic labels but does not seem to be distinct enough to warrant generic status.