David Tng

By day… I am a plant scientist. By night and in every other spare moment… I am a naturalist. I pursue and study a wide range of botany related topics ranging from plant photography, nature writing on blogs, building my plant Life List and volunteering as a demonstrator on how to use the online Australian Rainforest Key. Beyond the realm of the intellect…Underlying everything I do is an awareness of the mystical side of the botanical world. I aim to enhance the appreciation of plants with SCIENCE. I aim to infuse the study of plants with HEART. I aim to integrate the appreciation and the study with SPIRIT.

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A Meeting with the White Knights of Evercreech

IIt’s not a secret that the Eucalyptus regnans is the world’s tallest flowering tree and that Tasmania has some of Australia’s tallest old growth forests. So magnificent are these trees that significant individuals  have earned appellations such as ‘Centurion’ and ‘Methuselah’. Alas, the legend of the Eucalyptus regnans have overshadowed the other giants that reside in Tasmania. There are other giants among the eucalypts that are worthy of more general recognition, and it may come as a surprise to some that the White Gum (Eucalyptus viminalis) is one of them.

Practically every plant enthusiast in Tasmania and many tourists who visit the state has seen the grand forests of the Styx or the Tarkine. Few however, even among Tasmanian botanists, have met or are even aware of the giant White Gums of Tasmania’s Northeast. This is because White Gums are often thought of as average sized trees  associated with dry forest.

Yet, in the Evercreech Forest Reserve just 10 km from Fingal, a forest of gigantic white gums known as the White Knights preside over the wet forests. For centuries they have watched, like silent sentinels from their statuesque vantage point, the changing landscape of Tasmania’s Northeast. The time is nigh for the White Knights to take their rightful place in the annals of Tasmania’s rich botanical heritage, for nowhere else in the world does one encounter white colossuses such as these.

In the 1970s a forester named Des Howe was carrying out a routine survey in the forest about to be fell when he noticed that one of the trees that was to be felled was very tall. A surveyor came in and measured the tree to be an incredible 91m.  Girth-wise, the White Knight is just as impressive, being 3.3 m in diameter.

It is also believed to be over 300 years old, and due to the presence of this spectacular tree, 52 hectares in the area was made a forest reserve to preserve the White Knight and other giant White Gums that reside there.

The story goes that botanists initially did not believe that the tall tree reported by the Forestry Commission was a White Gum until leaf and fruit specimens were brought before them. Likewise for me, my experience of the white gum being a average size tree of dry forest was so ingrained that I would have scarcely believed that the White Knights were White Gums until I saw the characteristic seed capsules myself.

It is not difficult to see how the first foresters who came before the presence of the giant white gums likened the trees to Knights, perhaps spotting shiny-clad armour. White has always been the colour of purity and goodness, and there is nothing quite like the sight of these massive white boles standing in blazing contrast to a deep green forest understorey. And I am properly awed and impressed, just as the visitors before me that have come to pay their obeisance to the White Knights.

Almost a Flowering Plant: the Story of Gigaspermum repens

To the untrained eye it is possible to mistake certain flowering plants as mosses. Tasmania has a few examples, particularly some of the alpine bristleworts, which are small and turfed and even produce flowering stalks that superficially resemble moss capsules.

Much less likely is it for mosses to be mistaken as flowering plants, but yet, this was exactly what happened to a certain Australian moss by the name of Gigaspermum repens.

G. repens is a moss I had always wanted to see but Tasmania was not the best of places to be looking for it as it more typical of bare dry soils. This spring I was most fortunate to stumble on a small population near a rock outcrop on the summit of Mt Nelson.

The pale silvery quartz colour of the shoots were scarcely half a centimeter tall and reminded me of the ubiquitous Silver Moss (Bryum argenteum). Fortuitously, the plants I found were fertile, and in that state, there was absolutely no mistaking them. The fertile shoots were more than twice the size of the sterile ones and were, for lack of a better word, so pregnant.

Unlike most mosses which have capsules borne on a stalk held above the plant body, the capsules of G. repens were nestled among large modified leaves.

In this fertile state, plants are not dissimilar to minute flowers in bud. The capsule of Gigaspermum repens has a large operculum, or cap, which falls off when the capsules are ripe, leaving a great gaping mouth and exposing the characteristically large spores (hence ‘Gigaspermum‘ which means large seeds) that are just visible to the naked eye.

These large spores could be mistaken for seeds in a pyxidate capsule, a type of fruit in flowering plants like plantain (Plantago spp.) where the top falls off to release the seeds. The uniqueness of Gigaspermum has inspired bryologists erect a botanical family, the Gigaspermaceae, to accommodate it.

When the great 19th century plant collector Ferdinand von Mueller (1825-1896) found this plant, he allegedly thought it was a flowering plant belonging to the ice plant family (Aizoaceae) and named it Trianthema humillima.

Mueller was a first rate botanical collector and his incorrect description is no reflection of the lack of expertise on his part. Mueller was certainly aware of what mosses are. However, this episode does bear testimony to the morphological diversity that mosses can encompass, sans flowers.

The Flowers We Forgot

In my first days of botanizing, my eyes were glued on flowers. Flowers in the sense of trees, shrubs, twinners, lilies, irises, orchids, etc. These are beautiful, often showy, and definitely attention grabbing.

I was certainly not unique in my bias.

On the naturalist front for example, there are many whose passions seem to revolve around particular group of flowers.

Orchids appear to be one such group. Practically every spring there will be courses or fieldtrips held in appreciation of orchids.

Then also, there is the annually held Springflower Spectacular, ar show in the Hobart Town hall where a smörgåsbord of native banksias, boronias, daisies, heaths, peaflowers, and waratahs  are displayed.

Always this ridiculous obsession with flowers!

But misunderstand me not.

The motive of this writing is not to marginalize flowers, but to exalt them.

In all the time I have been looking at plants I  have yet to find a single flower that does not personify beauty. I am merely believing that an attention only to showiness and colour is myopic.

Admit we must, that most of us have cared little to appreciate a certain group of flowers ― the grasses and their inconspicuously-flowered kin. By these I am referring to sedges (Cyperaceae), rushes (Juncaceae), cord rushes (Restionaceae), bristleworts (Centrolepidaceae), waterribbons (Juncaginaceae) and any others that fit the  the bill.

So while roses, tulips, orchids and lilies are most often the subject of poetic adoration, I have come to absolutely adore the oft-quoted phrase from Walt Whitman’s Leaves of Grass:

I believe a leaf of grass is no less than the journey work of the stars.

The diversity of overall form in grasses and their kin is staggering.

They can grow as turfs or tussocks, as creepers or sprawlers. They can be messy or elegant. They can manifest as towering forms inspiring awe from the tallest of man (eg Cortaderia, Phragmites) or invoke adoration as minute annuals barely reaching a few centimeters (some Isolepis, Juncus etc).

But the true artistic genius of grasses and their kin lie in their flowers.

Grasses and their kin have flowers born in spikes, panicles or racemes, their spikelets displaying a bewildering configuration of shapes, sizes and orientations. When we finally get down to the actual flowers, we find that petals are simply not their style. They prefer the pragmatism of well hung stamens and plumed feathery stigmas that captures the love in the wind. Yet, unadorned as they are, their finesse is extreme, and their strategy hugely successful.

They are found from the edges of the sea to the tops of the mountains, in dryland, wetland, forest and scrub.

Where grasses occur in natural assemblages abundant enough to be the most dominant group of plants, they form grasslands. As an ecosystem, grasslands are richly diverse, supporting a wide range of invertebrates, birds and other plants. Many of Tasmania’s rare plants occur in grasslands. Such is the irony that we make annual pilgrimages to grasslands to look for orchids.

A ramble in a grassland evokes an inexplicable feeling in me. My mind conjures up a time when man has a primal connection with grassy, savanna-like environments. I can sense that the evolutionary journey of man and that of grasses and grass-like plants were always linked in some inextricable way. We eat of their substance. We weave of their resilience. As a whole, few plants groups has had as great an impact on man as grasses and their kin. I’d go as far as to say that the  form of grasses and their kin is etched into our psyche.

My journey has brought me to a point where I am thoroughly smitten with grasses and the like, just as I have become smitten with various other plant groups. I imagine this is the natural and inexorable progression of anyone who is assiduously and incessantly in search of more to appreciate. I know that until I fully expend my capacity to see and know all that I can see and know, my appreciation of this vast plant world can never be complete. And therein lies the joy of botany.

A Communion with the Miena Cider Gum

A single field trip up toward the Central Highlands offers plenty for a plant lover to see and do. One thing that must be done however, is to pay homage to the cider gums (Eucalyptus gunnii) of the highland areas.

 This cider gum is a tree of immense significance to Tasmania’s natural history. It is aptly named the cider gum for its sap, which has been reported to be used by the aborigines to make a much relished fermented drink (see article). I  was way too late to experience the spring sap that allegedly drips from the tree inviting all to partake of it’s sweetness. What would I give to try that out! It would be one of the most direct means of communion with the cider gum. On this occasion however, my objective was merely to make an acquaintance with the Cider Gum in its natural abode.

I drove along the Highland Lakes road north of Miena hoping to catch sight of some cider gums. There are two known subspecies, both of which are endemic to Tasmania. The more common one, E. gunnii subsp. gunnii (simply referred to as the cider gum) is well distributed throughout the highland regions of the southeast, central, and western Tasmania. The other subspecies, E. gunnii subsp. divaricata is known as the Miena Cider Gum, and has a much more restricted distribution to a small area around Miena around the Central Highland lakes. It’s status as a subspecies of the commoner cider gum wasonly recently elucidated in a publication by Prof. Brad Potts, Dr Wendy Potts and Dr Gintaras Kantvilas in 2001. Previously, the Miena Cider Gum was known as Eucalyptus divaricata.

I practically screeched to a halt when I sighted just by the side of the road, two large and stately trees which I suspected might be the Miena Cider Gum.

 I got out and scanned the surrounds. There were quite a number of dead trees in the vicinity but these two trees were different. They exuded a vibe of vitality. I studied them intently, looking out for characters that might give me an opportunity for identification.

A low hanging branch gave me access to photograph a cluster of their leaves and their capsules. The adult leaves also had a slightly pale whitish (glaucous) appearance and there was the persistence of very glaucous, rounded and oppositely arranged juvenile leaves.

Prof Pott’s paper had mentioned that the capsules of the Miena Cider Gum also tend to be more glaucous. The capsules are supposedly a slightly more sub-urned shaped compared to the more consistently bell shaped capsules of the commoner subspecies.

The combination of characters of the Miena Cider Gum seemed to match the specimen I was looking and I am happy to conclude that that was what my specimen was.

More important than the dry and technical act of nailing an subspecific identity to the tree however, was the feeling of communion. Few experiences compare to an acquaintance with trees of such haunting magnificence and presence. There is no words for it, only feelings that linger. Silence would probably make the best conveyance of this.





The Last Deciduous Tree in Tasmania

Introducing a tree that needs little introduction – Tasmania’s one and only native deciduous (meaning it drops its leaves in winter) tree species, the inimitable Nothofagus gunnii, the Deciduous Beech, the Tanglefoot. There are those too, who simply call it the Fagus.

The Deciduous Beech is a small tree from the beech family (Fagaceae). It reaches little more than 2 metres at the slightly lower altitudes but practically sprawls over boulders in the alpine zones. It is a mere dwarf compared to its much more widespread relative, the Myrtle Beech (Nothofagus cunninghamii).

A wild Nothofagus gunnii, the last Tasmanian deciduous tree (Photo by David Tng)

A wild Nothofagus gunnii, the last Tasmanian deciduous tree (Photo by David Tng)

The legacy of the Deciduous Beech, however, predates that of the Myrtle Beech. Fossils very similar to that of the modern day Deciduous Beech have been found in Antarctica, suggests that very similar species were in Antarctica before Australia separated from that now snowed out landmass.  The deciduous nature of N. gunnii also leads one to think that the habit of dropping leaves in winter might have been a much more common feature of the Tasmanian tree flora in times past.

Leaf detail of Nothofagus gunnii, the last Tasmanian deciduous tree (Photo by David Tng)

Leaf detail of Nothofagus gunnii, the last Tasmanian deciduous tree species (Photo by David Tng)

Alas, this is not really the easiest plant to visit, being a higher-altitude plant. The Royal Tasmanian Botanic Gardens (RTBG) has at least one specimen, but it is a small one hardly more than 50cm tall, and it is largely obscured by other plants.

Obscured! That’s ironic, particularly given that an illustration of the Deciduous Beech graces the signboard at the entrance of the RTBG. Still, that is one of the closest places to civilization that one may visit this icon.

A bonsai Nothofagus gunnii, the last Tasmanian deciduous tree (Photo by David Tng)

A bonsai Nothofagus gunnii, the last Tasmanian deciduous tree (Photo by David Tng)

Most understandably, the Deciduous Beech must be one of the most difficult-to-cultivate of Tasmania’s iconic plants. It takes a long time to grow, if it even survives. Still, once it harmonizes with a sincere plants-person, the Deciduous Beech will make a most exquisite bonsai plant.

Nothofagus gunnii in its native habitat (Photo by David Tng)

Nothofagus gunnii in its native habitat (Photo by David Tng)

But the connoisseur will seek the Deciduous Beech in its highest abode, in the  dolerite landscape of Mount Field National Park. The true seeker must travel to the mountains to the west, during April of the Southern Hemisphere autumn. They must drive west bound, up windy beaten roads, through the grand forest of the Mountain Ash. And where the road ends at Dobson Lake, they must traverse boulder and tarn by foot alone, beyond where the highland gums surrenders to frost and exposure. Then, and only then, does the sincere seeker arrive at the Tarn shelf, a true mecca of nival endemicity, where the Deciduous Beech basks upon the alpine boulders in its most exposed, most brazen magnificence.

And then one may say that one has witnessed the leaf fall of the last of Tasmania’s deciduous tree species, the yellow of the autumn Nothofagus gunnii.