Friday, September 9, 2016

King Orchids
Dendrobium speciosum var. hillii
(Thelychiton tarberi)

It’s king orchid time again, and these lovely plants are in flower in gardens, and in the wild.
Like all our native orchids, these are tough plants. You can see that this orchid is thriving in its very exposed situation, high on a tree in a degraded environment, where most of the original sheltering forest has disappeared.

It may have trouble making babies up there in its rather isolated site, though. First, it has to be found by pollinators, such as the stingless bee Tetragonula carbonaria. The chances are better when there are quite a lot of the orchids around top attract them, but it’s all a bit sad for the bees. Like most orchids, these lovely plants are “con artists”, attracting insects to do the hard work of transferring the pollen to other flowers, by promising nectar rewards with their shape, colour, and perfume – but not actually making the effort to produce any nectar. Working without pay is not fair in anyone’s book!
However, despite its fine show, this plant may be wasting its fragrance on the air. If no bee finds it, it will never produce seed, a continuing problem it shares with many of our native plants as our bushland is ever more segmented and it gets harder for the increasingly isolated plants to attract pollinators.

Unlike some of their closest relatives, king orchids are tree-dwelling plants. Their fine seeds are happy to germinate on the rough park of perfectly straight trees like the one below. All they need is for the right kind of fungus to be already there, to help the helpless little seeds to begin growing.

And orchid seeds are unusually helpless, which means they must become parasites from birth. Most parent plants provide their seeds with a little food package (endosperm) to feed the newly germinating baby plant. Orchids, in their enthusiasm for producing enormous numbers of their very tiny seeds, neglect this rather basic precaution. If none of their seeds can latch onto a suitable fungus nursemaid to provide them with the necessary nutrients, then the orchid’s efforts to create a new generation will fail.
Orchids are one of the most successful plant families in the world, proving that, all things being equal, it pays to be a user. All is not equal in our local environment, however, and our district’s once-rich orchid flora is dwindling away.
All praise to those who give it a chance to recover, by conserving and restoring patches of our local bushland.

Sunday, July 31, 2016

Forest Daisy

Brachyscome microcarpa
As usual in our fortunate part of the world, signs of spring appear almost as soon as the signs of autumn have gone.
Trees are bursting into new leaf, birds are looking around for mates, and little daisies are starting to open their bright eyes.

We have so many native daisies, that it can be difficult to identify them all. This one, however, is distinctive, with it’s unmistakable leaf shape, and its (relatively) large mauve flowers.

A plant of eucalypt woodland on light, well-drained soil (such as at the Bunya Mountains), it could make a useful, ankle-high ground-cover.
It prefers to grow in dappled shade, and where there is not too much competition from other plants.
It is commercially available (in several colour forms), but it may be difficult to buy plants of local provenance.
Once established, this is a plant that would need little care, resisting both drought and light frost.

Tuesday, July 5, 2016

What’s Good about Lantana?


It’s easy enough to list the things we Australians DON’T like about that invader from South America, Lantana camara. Alas, that we inflicted it upon ourselves, with our careless gardening habits!

1. It colonises disturbed soil with dense shrubbery, 2-4 metres tall, crowding out smaller plants and preventing regrowth of native trees.
2 As the native vegetation is lost, so is the wildlife that depended on it.
3. Lantana behaves as a nurse plant to privet, an even worse, tree-sized weed, enabling it to establish a virtual monoculture on what was previously rainforest land. The privet forest on the Eastern slopes near Toowoomba, is a classic example of this.
4. Lantana has huge economic impact, reducing the productivity of pastoral and forestry land.
5. Its leaves are poisonous to stock, (some varieties more than others).
6. It’s a prickly, scratchy nuisance to bushwalkers.

Lantana has some Good Points Too
Whenever a super-weed like lantana creates a new environment, some native animals will find a niche to their liking, and thrive.

1. Small birds like wrens find lantana thickets an ideal place to live, eating the succulent fruits, and building nests in the scratchy thickets.
2. It shelters small mammals, such as antechinus, bush rats, and bandicoots.
3. Reptiles, especially small skinks, make use of the shelter.
4. Butterflies love the nectar-rich flowers, which provide them with food over a long season (albeit while slowly exterminating their species by crowding out their host plants).
5. The pithy stems are used as homes by the primitively-social reed bees (Exoneura species). These bees are important pollinators of native plants.
6. It improves soil quality, and controls erosion on slopes.

Does this mean we should love lantana, after all?
Well, no. Not really.
A natural mixture of native plants is the basis for a richer, more varied ecosystem. It hosts more kinds of birds, mammals, reptiles, and insects than lantana ever could, and stabilises the soil just as well.
But lantana’s good points can be a reason for avoiding the “bull at a gate” approach to removing it. We have to keep in mind that clearing weeds is not a beneficial environmental activity in itself. It’s what comes after the clearing that matters. If no thought is put into where they are to go, those little creatures which managed to make lives for themselves among the weeds, then clearing them only causes a net loss of biodiversity.
“Softly, softly”, is the answer.
If we’re hoping that natural regeneration of plants will provide for the displaced wildlife, we need to clear in small doses, and monitor whether regeneration, of the kinds of plants we were hoping for, is really happening.
Were our expectations unrealistic? If clearing doesn’t result in a cheering surge of new growth - and it often doesn’t in our dry and erratic climate - then active revegetation is needed. Plants must be planted, and tended until their survival is assured, and meanwhile, the cleared area will need constant weeding of lantana (and other weed) regrowth so the carefully-planted seedlings aren't lost to shading and root competition. Too many bushcare projects have been sent back to square one by lack of follow-up!
Working with nature is the way to go, when revegetating. A half-and-half approach, blanket planting planting pioneer species to modify the environment, can provide both fast shelter for wildlife and a suitable mileu for natural regeneration of  longer-lived species. This only works if there is a natural seed source nearby, of course. Revegetation of rainforests and scrubs, on the other hand, can be slowed down by mistaking fast-growing dry sclerophyll plants such as wattles and eucalypts for pioneers, though. These greedy plants rob the soil of moisture, slow down the growth of other plants, and simply establish themselves as the dominant vegetation.
Sometimes, the best approach to clearing lantana consists of leaving it alone for a few years, and getting on with planting, instead. Once refuges for wildlife have been established, the clearing can go ahead - but always in proportion to the shelter available.
Now is the time to be planning it. The frosts will be over before very long.

Thursday, June 30, 2016

White Cypress

Callitris glaucophylla

This is one of our most underestimated local plants. It deserves to be used more often in gardens, streets, and parks.
Its neat shape makes it suitable for formal situations

The fine, dense foliage makes it a useful contrast plant, when grown with other types of trees, as shown here in a natural situation at Maclagan.

Despite its name, individuals of this species vary in leaf colour, from the “white” (really blue-green), to a clear green. In the wild, plants of a variety of canopy colours often grow side by side.

Mature trees reach a height of about 18 metres.

Young trees may respond to damage by producing more than one trunk. For a cypress, pruning or trimming the foliage counts as damage, and is best avoided. Gardeners should supervise their young trees, and if any show signs of producing a second trunk (or more) to compete with the main trunk, these should be removed as soon as possible.
Older trees, however, benefit from tidying up by removal of dying lower branches, to neaten their trunks.

The new season’s cones are starting to be seen around the district at this time of year. Male and female cones are found on the same trees.

As with all conifers, the male cones (above) shed masses of pollen.
They depend on the wind to transfer their pollen to female cones. This is a rather hit and miss method. Unlike those plant species whose pollen is transported efficiently from flower to flower by insects or birds, they can’t afford heavy pollen, but must produce something light, and lots of it, so that at least some of it finds its way to its target.

Once pollinated, the female cones grow into this attractive spherical shape.

Later in the season they will split open to shed their small winged seeds.

White cypress is the famous timber tree, often called “cypress pine” although strictly speaking cypresses are not pines. The honey-coloured timber is an Australian classic, well-known for its use in house frames, floors and decking, where its hardness and its resistance to white ants (termites) and Lyctus borers is an important quality.
However it is also a good ornamental timber, attractively marked and taking a high shine.

Saturday, March 26, 2016


(Yam Daisy)                                                        
Microseris lanceolata,  

This small perennial has yellow flowers similar to a dandelion.
It was once one of the most important food plants for Aboriginal people of the grassy plains of southern and eastern Australia.
The small sweet tubers are produced each year in early spring, and harvested in summer (about November). In a typical example of the semi-agricultural practices of the Aborigines, smaller tubers were left in the soil, and meanwhile the soil-loosening effect of the digging sticks used by the harvesting women provided good growth conditions. Old records tell of hundreds of women spread across the plains at harvest time, all digging for these nutritious roots.
The plants die back to their underground roots in March, and begin putting up new rosettes of fresh leaves in Autumn. The grasslands where the murnong grew were burned off during this dormancy period, with the burning controlled so that only some patches were burned each year. The whole growing area was burned every 3 years. This controlled the growth of larger plants, which would otherwise have shaded out this valuable food crop.
The roots are washed, then roasted for about 10 minutes. They become soft and rather syrupy-sticky, with a sweet flavour which some people describe as resembling coconut, or a sweet nut. Modern recipes recommend little olive oil and a dash of salt and pepper.

My pot-grown plants produced rather small roots, so I have moved them into better soil, and hope for a better crop next year.

The following sequence shows the interesting development of  the dandelion-like flowers. Their heads droop modestly until the flowers open, then it is time to lift them and attract pollinating insects. They stay upright for just one day, then droop again as the seeds form. When the seeds are ripe, the stems elongate and straighten, holding the seeds up to the wind, for distribution.



As with all daisies, each “flower” is really a bunch of tiny, individual flowers. In murnong, they have  just one petal each.

Murnong is one of Australia’s best bush foods. The prominent 19th Century botanist Ferdinand von Mueller thought it was so valuable as a food plant, that it was the only Australian plant he recommended for development as a crop for white Australians.

Unfortunately, the wild plants, which once attracted people in their hundreds for the annual harvest, grew in the same grasslands as the white settlers coveted for sheep pasturage. Early records say that sheep loved it so much that they would eat the leaves and dig up the roots. (Some accounts say they did it with their hooves. Others say they dug them up with their noses. Perhaps someone who knows sheep better than I can clarify this!) Some squatters claimed that their sheep lived almost entirely on murnong for their first year, on their newly claimed pastures. Whatever digging technique they used, they would exterminate most of the plants in the first year. They rapidly drove the species to extinction over most of its range, causing disaster for the people who depended on it for food.

We will probably never know whether it once grew widely on the Darling Downs. The only record of it being found here, that I know about, was of plants growing naturally at Gladfield, near Cunningham’s Gap, in 1891 - 50 years after the squatters arrived with their flocks and herds.

This is a very tolerant plant, growing well in a range of soils, from acid to alkaline. It tolerates drought and frosts, but no more than very light shade.

Sunday, January 24, 2016

Giant Pepper Vine

Piper hederaceum

The storm the other night brought down this sprig from a giant pepper vine in Goomburra National Park.

 These fruits would have been preceded by tiny white female flowers, fertilised by the male flowers (which grow on the same plants as the females). I haven’t ever seen them (they tend to grow too far up in the rainforest canopy), but am told that they have a strong perfume.

A few giant pepper vines can still be found in the rainforest remnants on Toowoomba’s eastern escarpment. In earlier times they were so common in the Toowoomba district that they had a reputation for causing a major summer influx of white-headed pigeons, as they came to feed on the ripe fruits. This tells us something about how very much our local vegetation has changed since then. Anyone seen a white-headed pigeon lately?

Pepper vines have ornamental potential. They can be used both as small plants in hanging pots (in a shady spot where their broad “shade-leaves” would show to advantage) ....

or on a strong trellis or pergola of the sort that we more often see covered with Wisteria. Used the latter way, the pepper vine’s smaller “sun-leaves” would create a shady arbour, and the pretty summer fruits could be seen (together with the birds they would bring to the garden).

Curiously, the flowering stems produce even smaller leaves if they are going to flower. This lets us know when flowers and fruits are “in the pipeline”.

Giant pepper vines begin life as  root climbers, ascending the smooth surfaces of trees or rocks (or, potentially, a shady brick wall). This tendency to climb like ivy is the reason for its name “hederaceum”, a reference to the Latin word hedera, for “ivy”.
Here’s one whose high hopes are about to be dashed!

Stems of mature plants lose the clinging roots. However their nodes where leaves and roots were once attached, continue to be marked by distinctive rings. Pepper vine trunks are easy to distinguish from all those unidentifiable climbers that disappear up into the rainforest canopy.

The root-climbing habit gives giant pepper vine a tendency to cling rather closely to its supporting frame, clothing it in greenery and outlining its silhouette.
This dead tree has acquired a very quaint appearance! 

Fortunately for the beauty of the rainforest, the pepper vines avoid the smaller stems, so the host trees' own canopy is never overtaken by its pepper vines.

Stems which find nothing to cling to do not build high bulk, as with some climbers, but hang downwards in long festoons, sometimes almost reaching the ground. The effect, as they sway gently in the breeze, is cool and attractive.

Growers of the related Indian pepper of commerce (Piper negrum) say their plant restricts itself to whatever size of trellis it is given. Clearly ours would do the same. The festoons could be trimmed off if neatening is required. In the case of a pergola, they could be left to form curtain walls.

The Festoon Falls in the Bunya Mountains were named after a magnificent curtain of pepper vine, which enclosed the falls. My mother remembered it from her youth, but said it was destroyed in a cyclone “round the time of the war”. If you visit the site, you can see that the enormous trunk of the vine still grows at the top of the falls, but that the supporting trees from which the curtain used to hang have gone. The existing trees now support a few festoons...

... but it will be many years before the whole curtain will be restored.

Giant pepper vine is a frost tender plant. It grows moderately fast in Toowoomba’s climates, including its droughts, if it is in a shady site with well-mulched soil. Like all rainforest plants, however, it grows even faster if watered.

About Pepper
Worldwide, there are approximately 1,000 species of Piper.
Although the fruits and leaves of many of them are used in cooking, the best-known is , the source of the common pepper we buy in the supermarket. It is imported from Southern India, and the same plant is used to make white, black, green and red pepper.
White pepper is the hottest form, and consists of the naked seeds of green-picked fruits. They are separated from the flesh by soaking in a hessian sack for several weeks, causing them to ferment. Then they are trampled and washed until none of the fruit or skin remains on the seeds.
To make black pepper, the green fruits are spread on a cloth to dry in the sun. Their tangy black pepper flavour is developed by enzymes present in the fruits, as they dry and change colour.
The green-coloured pepper seeds we buy are “hot”, like the black, but not particularly flavoursome. The green colour is fixed by plunging them into boiling water for twenty minutes (to kill the enzymes), then sun-drying or freeze-drying them. Despite their inferior taste, there is a commercial demand for them, to enhance the appearance of mixes used in transparent pepper mills.
Left to ripen on the vine, pepper fruits turn yellow, then red. Dried ripe fruits are considered to have poor flavour and are rarely used, except in the same ornamental pepper mixtures. Their colour may be retained by freeze-drying, but  a commonly used commercial technique is to treat both red and green peppers with sulphur dioxide. While it preserves the bright colours, it has no appeal for those who would rather avoid unnecessary chemical additives in their food.
Pepper fruits can also be used fresh. The green ones are a staple of Thai cuisine. The red have a distinct fruity flavour.
Our native Piper hederaceum seeds less hot than Piper nigrum, but have a pleasant spicy flavour.

Friday, December 4, 2015

Lovers Twine

Glycine clandestina


This is a pretty irritating little plant.

At its best, which it is at this time of year, it is pretty, with its clusters of little mauve flowers liberally sprinkled over the plants, which twine up through other plants in the garden, never climbing higher than about 60cm. It’s so pretty that I wonder why I am such a grump as to find it irritating for most of the rest of the year.

But I do.

It’s just that it spreads so sneakily, spreading through the garden, producing so many of its thread-like little twining stems that they go into tangles, neither very pretty once the best of the flowering is over, nor really ugly enough for me to make a serious push to get rid of them completely.

Not that I ever could.

The fine stems also spread unperceived over the ground, rooting at the nodes. Each root grows into a little tuber like a miniature parsnip, making it impossible to pull the plants out. The fine stems simply break off. To get rid of them is a matter of digging out the tubers individually.

And the flowers all produce hairy little pea-like pods of seeds, so new plants spring up all over the place.

Some gardeners seem fond of them, and say that they “prune” them, and get more attractive plants as a result. “Pruning” can be done, and does reduce the general messiness. It consists of combing the fingers through the tangles of lovers twine, pulling it off the other garden plants, until the patch of garden is reduced to a reasonable appearance.

the plants bear some resemblance to that other little native purple pea, Hardenbergia violacea (below). Hardenbergia, however, flowers earlier in the year and  has single leaves...

while the leaves of lovers twine are trifoliate.

Unlike some native peas, glycines can safely be eaten by stock.