Tasmanian Plants

I have deep respect for ferns living in harsh conditions and one such fern is  Asplenium obtusatum (Shore Spleenwort). This species is also present in New Zealand but the Tasmanian form is known as A. obtusatum subspecies northlandicum, a form that was described by the renown pteridoloist Pat Brownsey in 1977.

The Shore Spleenwort is allegedly common and grows on rocks along the coastline of Tasmania. Widespread as it is, I’ve only had the fortune of observing it growing on the cliff faces around the Remarkable Cave in the Tasman Peninsula and in the fernery of the Royal Tasmanian Botanical Gardens.

The fleshy and shiny fronds of this fern makes it instantly recognizable and reminds me of the Sea Spleenwort (Asplenium marinum) of the Northern Hemisphere, a fern I would very much like to meet. Being ferns of such similar habitats, I imagine some convergent evolution in form is at work here.

Asplenium obtusatum is tolerant of some salt spray, a remarkable feat indeed given the vulnerability of ferns during the earlier stage of their life cycle.

This earlier stage are known as the gametophyte phase, as opposed to the sporophyte phase that we call ‘ferns’. The gametophyte is an inconspicuous little liverwort-like a structure that germinates and develops from fern spores. In most botany textbooks the fern gametophyte is portrayed as a heart-shaped structure and is called the prothallus. It is from the prothallus that the male and female reproductive parts develop. When the time is ripe for fertilization, the sperm swims through a film of water to find an ‘egg’ to fertilize. From this union, a baby fern is born, growing out of the tissues of the prothallus. The cycle is complete.

Unlike flowering plants, the fertilization of ferns require a film of water as mentioned above. Imagine the physiological stresses that a fern prothallus has to endure when the occasional salt spray comes into the picture!

The Shore Spleenwort is indeed a hardy fern worthy of a lofty station by the magnificent cliffs of the Tasmania coast!

Hybridization as a means of making new species is not an uncommon concept and hence it must be applicable to other species. I present a case using a Tasmanian example – the Olearia daisybushes.

Olearia is a large and conspicuous genus of shrubs in the sunflower or daisy family (Asteraceae) with some 23 species in Tasmania of which 8 are endemic to Tasmania (not counting subspecies).

Left: Geebung Daisybush (Olearia persoonioides); Right: Prickly Daisybush (Olearia pinifolia); Centre: Possible hybrid

Two of the endemic species are of interest in this post: Olearia persoonioides (Geebung Daisybush) and Olearia pinifolia (Prickly Daisybush). Both are common and largish daisybushes that grow in subalpine woodlands.

Whilst botanizing at various spots around the Central Highlands I stumbled upon the two species of daisybushes growing in close proximity in the understorey of a eucalypt woodland. They were both in full flower. At the same time I also noticed numerous specimens that looked like intermediates between the two.

While this intermediate specimen deserves much more detailed study, I have prepared a set of photographs and made a table of the characters comparing the two daisybush species with the intermediate specimen.

Many additional aspects of the morphology of the intermediate specimen deserves study. For example, the morphology of the flowers and fruits (achenes) needs to be examined in greater detail. Other studies like chromosome counts might also be helpful in determining the hybrid status of the intermediate specimen.

A trip to the herbarium is in the works!

The Blue Gum (Eucalyptus globulus), Tasmanian Waratah (Telopea truncata), Deciduous Beech (Nothofagus gunnii), Myrtle Beech (Nothofagus cunninghamii) and Pandani (Richea pandanifolia) are names that are often cited by plant enthusiasts and bushwalkers guidebooks as ‘must-sees’ of Tasmania.

But these five iconic plants, showy and famous as they are, must defer to THE ONE TRUE ICON plant that represents Tasmania — the Delicate Laurel (Tetracarpaea tasmannica). The popular portraiture of Tasmania’s botanical gems must be expanded to exalt the Delicate Laurel and to remedy it’s unfortunate oversight.

(Yes I am being evangelical).

The Delicate Laurel is by no means an uncommon plant. It occurs in wet forest or more often, subalpine shrubberies in the western mountains. The plant blends quite immaculately into the surrounding scrub and is not extremely prominent unless in flower, the erect flower stalks bearing small odd-looking white flowers with 4-5 oversized carpels (female parts). Without consciously looking for it however, Tetracarpaea would be quite easy to overlook whilst hiking pass the lush shrubbery vegetation. Once known however, the plant is easily recognizable by it’s thick leathery serrated leaves. The brown dry fruits (folicles) are also quite distinctive.

Distinctive as it is, the history of how the plant was named and classified has been fraught with difficulty and confusion (See Tasmanian Flora online profile).

The eminent botanist Joseph Dalton Hooker is often attributed with having named and described the plant in but it has only recently been clarified that it was his father, Sir William Jackson Hooker that had found and described the plant (The original illustration of the plant in Sir William Hooker’s Icones Platarum may be found here). It was also only recently that the correct species epithet ‘tasmannica‘ was reinstated, as opposed to the commonly but mistakenly used ‘tasmanica‘.

Botanists also have had difficulty determining the affinities of this enigmatic little shrub. They variously thought it to be related to the Horizontal bush (Anodopetalum biglandulosum), the Native Laurel (Anopterus glandulosus), and even Saxifrages. Only recently have molecular methods demonstrated that the closest relatives of Tetracarpaea are actually raspworts (Gonocarpus spp. and Haloragis spp.) and watermilfoils (Myriophyllum spp.). Still, the unique traits of the Delicate Laurel dictate that it is best placed in a family of it’s own, the Tetracarpaeaceae.

So there we have it. A true botanical orphan found ONLY in Tasmania.

The ONLY species in the genus.

The ONLY genus in the plant family Tetracarpaeaceae.

A prime example of Tasmania’s botanical heritage.

Forget about beeches, waratahs, pandanis and blue gums for a moment. These long revered icons have been discussed, photographed, drawn and stylized in Australian art ad nauseum. A true connoisseur of plants visiting Tasmania for the first time must embark on a montane pilgrimage and pursue first and foremost the one and only Tetracarpaea.

There are rather few genera of native Tasmanian plants that share the same genus as the common economic food plants we see in the market everyday. Some examples might come as a surprise however. For instance, Tasmania has one native plant which is a close relative of the CARROT!

The carrot of commerce is botanically known as Daucus carota spp. sativa. In the wild, the species is often referred to as Wild Carrot or Queen Annes Lace. The carrot belongs to the Celery family (Apiaceae), a large botanical family which also includes many plants which will immediately be familiar to the general public, eg fennel, parsley, parsnip, pennyworts, caraway and even hemlock, the source of the poison that killed the famous Greek philosopher Socrates. While the carrot is probably one of the most well known, the genus Daucus actually consists of some 60 species worldwide.

When I saw Tasmania’s answer to the fleshy and succulent carrot of commerce I was pretty amused. This was a small grassland herb, the Australian Carrot (Daucus glocidiatus), which would easily be overlooked as some inconspicuous weed.

Unlike the Wild Carrot, with numerous flowers in showy umbels, the Australian Carrot has a few inconspicuous whistish-pinkish flowers borne on an irregular umbel.

I try not to pick entire plants if I can help it (pretty wimpy for a botanist I know) but I couldn’t help it when it came to this little herb. I just had to check out it’s subterranean parts to see if there was anything carrot-like about this curious little herb.

Turns out that the Australian Carrot does have a taproot but nothing that a bunny would pause at to consider. The affinity of the Australian Carrot to the carrot of commerce had to lie somewhere else.

In the field this little herb is rather easy to identify. Few other native grassland herbs have such finely dissected pinnate leaves. In particular, the small bristly fruits make it instantly recognizable.

And indeed, it is probably the fruits that betray the affinity of the Australian Carrot to the carrot of commerce. In both species the fruits are bristly. In the Australian Carrot, the bristles on the fruits are barbed, as alluded to by the specific epithet ‘glochidiatus‘, which means barbed fruit.

In European herbal lore, the seeds of the Wild Carrot is known to have contraceptive properties (see webpage). If we were to make some extrapolations and speculate, could not the seeds of the Australian Carrot also be used for similar purposes? There certainly is the potential for such medicinal research on native plants.

In my virgin 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 biasness.

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 obeisance of orchids.

Then also, there is the annually held Springflower Spectacular, a public springflower show in the Hobart Town hall, where a smörgåsbord of native banksias, boronias, daisies, heaths, peaflowers, waratahs etc 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 smittened with grasses and the like, just as I have become smittened 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.

What do you do when you are faced with something that is an unbearably adorable?

There is little recourse but to fall head over heels for it.

For many people the object of adoration may be a puppy, a kitten, a small fat chirping birdie, or some other cuddly animal. Seldom have plants been viewed as cute or adorable.

Yet everytime I encounter a plant in turfed perfection (being small accentuates this), with scapes of flowers or fruits pointing heavenwards, I start experiencing a fluffy feeling inside similar to that a kitten evokes in me in it performs it’s cutest antics. I’d call this the unbearable adorableness of turfed existence.

One of the many plants that fall under such a category is the Hairy Bristlewort (Centrolepis strigosa) (Just so you can have a feel for how small bristleworts can get, the picture above was taken with a $2 Australian coin which is roughly 2 cm in diameter).

I made my first acquaintance with this common plant a year ago in the Northwest part of the state and I have been finding it everywhere since. But everytime I see this little plant I cannot help but want to take a picture.

And as you would no doubt have surmised, I don’t stop myself…