Tuesday, December 30, 2008

Beautiful Brachychitons


Our neighbour’s flame tree is late.
My camera has spent most of the past week focussing on family faces, but I couldn’t resist letting it peek over the fence at this tree (Brachychiton acerifolius), flowering its little heart out when most of its kind have given up for the year.
Flame trees are a local native species in no danger of disappearing thanks to their popularity in gardens and as street trees.
Two other local Brachychiton species are also familiar to most of us. Bottle trees (Brachychiton rupestris) and kurrajongs (B. populneus) are often seen in the bush around the district, as well as in gardens (though kurrajongs are not grown as often as such hardy, shady trees deserve to be).
A less familiar sight is the lacebark tree, Brachychiton discolor. This rainforest species would once have been quite common around Toowoomba, and can still be found in a few scrub remnants at Highfields and Gowrie Junction. Its felt-textured pink flowers are produced during its long summer flowering season, which begins (as with flame trees) with a leaf drop in early summer, and ends with the production of the new year’s leaves.
This photo shows the graceful white trunk, which swells slightly near the base, revealing its relationship to bottle trees. It was taken on the western side of Mt Kynoch, on an exposed knoll in what is now a grassy paddock. For it to have thrived in infancy, this must once have been quite a different environment, with soil covered, in damp leafmould and sheltered by a canopy of similar trees. This tree is doomed to be childless, as there is no chance that its seeds could germinate naturally on that site, nowadays. It stands alone of its species, evidence of the rainforest that must once have clothed the hillsides above Gowrie Creek.

Another rainforest relict on the same hillside is one of Toowoomba’s last naturally-growing treeferns, Cyathea cooperi, looking out of place amongst the privet and lantana that now dominates its little creek-bed.

Here is the view that the lacebark tree has.

It looks west across the width of Toowoomba, all the way to Gowrie Mountain, and must receive the full force of our cold, dry westerly winds in August. Its ability to thrive and flower in this radically altered environment demands our respect - and tells us what an adaptable garden plant it can be.
Lacebarks are fast-growing and long-lived. Smaller than flame trees, they are better suited to suburban gardens. Their old environment has dwindled to vanishing point in this district, but I hope that we will continue to see them here, as gardeners see the value of growing our local natives on the soil where they truly belong.

Saturday, December 20, 2008

Holly Dovewood

Alchornea ilicifolia
An internet search told me that no fewer than 17 Australian native plants have been given the common name “native holly”, despite being unrelated to the well-known Christmas decoration species, English holly Ilex aquifolium. We sometimes see English holly grown in gardens here, but it is disappointing as a Christmas decoration as it produces its berries in winter. The leaves and fruits are both toxic to children, and altogether it seems to be a plant that Australians could give the go-by.
There is a genuine Australian holly, Ilex arnhemensis, which grows in the Northern territory. As its leaves are very ordinary-looking, with no hint of the toothy edges which give the other “native hollies” their nicknames, it’s never been suggested as a native Christmas decoration.
Sprigs of our own local holly dovewoods, however, are one of the best substitutes for the “real thing”. The tough leathery leaves keep well, looking good for at least four days without water (though the fresh new leaves wilt sooner than that).
As garden plants they are more attractive than English holly, their new leaves ornamenting the plants with lovely shades of bronze. They lack the red fruits, though. The green seed-capsules (found on female plants only) ripen to brown.
When young, holly dovewood makes a good indoor plant. Like most of our dry rainforest plants it can be trained in the shape of a small tree, suitable for a suburban garden. It is best grown as a shrub, however, where it needs only occasional pruning to keep it as a dense, bird-sheltering screen. The leaves are mildly prickly, so it is also suitable as a border hedge where you might want to discourage intruders.
This is a drought-hardy plant which can be grown in full sun or bright shade. It does appreciate shelter from heavy frosts in its first few years. (It seems to survive them, but can look a bit bedraggled from frost-burn.)
The story is told that the plant has white latex, which could result in eye damage to careless humans. Being a cautious sort of person, I included a warning about it in my book (“Toowoomba Plants Vol 1") despite having being unable to find any sign of latex in my own plants. It can be difficult to get latex from some known latex-producing plants when they are drought affected, so I assumed that this was the reason. However, despite the good season I am still unable to find any sign of white latex, and now suspect that this is an example of the sort of factual error that does get made about of our local native plants, simply because they are little grown and poorly known. If any readers can contradict me, I would be delighted to hear from them!

Saturday, December 13, 2008

Consider the Lilies

Here is a selection of locals:

Dianella caerulea
Typically a plant of our open forests, this grass-like plant forms a tuft up to 45cm across and about the same height. It is quietly attractive even when not in flower. The summer flowering stems reach to twice the height of the leaves, and have dainty flowers followed by showy blue fruits.
They are drought, frost and sun hardy plants, often chosen by landscape architects for bordering paths, adding linear accents in flower gardens, scattering among shrubs, planting in massed groups to exclude weeds, interspersing with grasses in planted meadows, or taking indoors in pots.
Another common name for them is “flax lilies”, as nineteenth century research found that a high-quality fibre of commercial quality - perhaps high enough to make good linen cloth - can be obtained from them. That this has not been followed up has more to do with the absence of need for another fibre crop, in this age of synthetic materials, than from any inadequacy on the part of our local native plants. The original Australians used them to make string bags and baskets of very good quality. Hobbyists may consider them worth growing for spinning, weaving, or basket-making. (The fruits have also been used to make a blue dye.)
The modern bushfood craze has seen the fruits being eaten raw, though the flavour is rather insipid. Traditional aboriginal use of the plant, however, seems to have been limited to eating leaf bases or roots after preparation. Some of the species have irritating berries, and there is some question about the safety of fruits of all the species. D. caerulia is has been pronounced by some authors to be safely edible, despite great variations in the results of scientific tests. If you must experiment, don’t give them to children, and limit your own consumption to small amounts.

Thysanotus tuberosus
It’s easy to think you’ve lost this lovely little plant, as it dies back to its underground tuber each year. It actually is quite easy to lose, though, as it depends heavily on a certain soil fungus. Inoculation with fresh soil taken from around established plants may help.
The plant is so lovely, though, that it’s worth going to some trouble to grow it. It needs well-drained soil and dappled shade, and doesn’t like close competition from taller plants.

Murdannia graminea
These plants grow particularly well on the bora ground at Gowrie Junction, in the very shallow soil among the basalt rocks. They also like dappled shade among eucalypt trees, often at their best in the summer after a bushfire.

The three-petalled mauve flowers are closely related to “wandering jew” - but they don’t wander at all. They can be produced prolifically, on each little plant, after rain in summer. They open fully only when the plant is in sunlight, and close when shade comes across them.
When not flowering, the plant’s grass-like leaves are inconspicious. It dies back to an underground tuber each year, thereby surviving difficult droughts and harsh winter frosts.

Crinum flaccidum
These are plants of river flats, where the soil is occasionally flooded.
For most of the year, they exist only as large (1kg) underground bulbs. In late winter, some flaccid leaves appear, and sprawl messily across the ground. The sweetly scented flowers appear after summer rains.
The bulbs are capable of burrowing! By contracting their roots, they pull themselves down through the surface soil of their loamy habitat until they reach the underlying clay, as much as a metre below the surface.
There, they are sheltered from extremes of weather until summer, when the warmth and the rains penetrate deep.
Gardeners should plant the bulbs with their tops about a handspan deep, and let them find their own level.
They reproduce by bulbils which form at the bases of the dying flowers (so don’t trim them off!) They contain their own water supply, and can germinate without any added water. They are worth planting even though they might, in very dry times, take up to 10 years to flower.

Proiphys cunninghamii
This lovely plant grows on red soils in the wetter parts of the region, in Eucalypt forests or the edges of rainforests. In the garden, they look their best if the sun rarely touches them. They like fairly good light, though. These are not indoor plants!
Mine spend two-thirds of the year in a pot on a shade-cloth-covered patio. They get put away in the bush-house over winter when they lose their leaves.
Beautiful, heart-shaped, dark green leaves appear in spring, and grow up to 50cm high. The heads of up to a dozen gleaming white, fragrant 3cm flowers appear about Christmas time. As they die, round green bulbils develop behind each flowerhead. These ripen to orange, at which point they are ready to plant. They take two years to reach the flowering stage, by which time the bulbs are 5cm in diameter.
The plants don’t like to be disturbed when they are in their leafless phase, so moving and dividing is best done in summer after they flower.
They need protection from frost.

Commelina diffusa (Commelina cyanea)
This is our common native blue-flowered "wandering jew". It’s one of those plants that people seem to either love or hate. It’s very pretty at this time of year if well watered, but it tends to be invasive.
I let it grow in the rougher places about the block, but weed it out - never with complete success, in the gardens close to the house. It certainly has potential as an ornamental plant, but would need to be grown a confined place, and cut back firmly - even mown - when it starts to look straggly.
Frost knocks it, but it regrows from its roots.

Barcoo Rot

Early white settlers in the outback typically depended on “supplies” brought to them by bullock wagon, and later by train. The bulk of these consisted of flour, tea, and sugar. Meat they had, since they rode on a wave of pastoral expansion, or could always shoot some of the native animals. Fresh fruit and vegetables were a luxury, often hard to obtain due to the unreliability of both water supply and knowledgeable gardeners.
The link between the disease known as “Barcoo Rot”, and the lack of vegetables was not made until some time after it was known that lack of vitamin C caused scurvy. Scurvy was seen as a disease of sea-goers, and the idea that the sufferers, far inland, of the “rot” had actually contracted scurvy for the same reason that sailors did - the lack of fresh plant food - was slow in coming.
Once the concept was understood, however, (and the phrase “Eat your greens” entered the vocabulary of mothers the world over) Australians looked around them for plants which could solve the problem. Native plants with edible leaves found new respect, despite their often rather ordinary flavour. “Wandering Sailor” - also known simply as “scurvy weed”, was one of them.
Aborigines, incidentally, rarely ate leaves. They obtained their vitamin C from the very large number of edible fruits which surrounded them. These were not usually obtainable in belly-filling quantities, and were usually treated with contempt by white settlers who saw no point in eating tiny quantities of fruits of unappealing flavour, often consisting mostly of seeds.

Thursday, December 4, 2008

Bumble trees - our local native capers

Capparis species
This is one of my favourite trees. It’s a venerable old bumble tree, Capparis mitchellii, out at Lake Broadwater (west of Dalby). The photo shows the break in the canopy, where perhaps another tree once grew. Capparis species often start life at the foot of another tree, appreciating the shelter, and behaving like climbers, using their thorns to climb up their neighbour.

Whatever the reason for it, this gap is now a favourite shady resting spot for kangaroos.

Here are some unripe fruits from the tree, which is the largest-fruited of the native capers. (Note also the butterfly eggs in this photo).

Overripe fruits turn orange, and smell like rotten oranges. They have earned the tree the common names of "Native Orange", "Wild Lemon", and "Native Pomegranate", although they are really like none of these things.
They are edible, when soft, but still green in colour.

Capers are one of our most valuable butterfly hosts. Five local species of caper butterflies breed on nothing else, and the plants can be spotted from afar because of the fluttering host which surrounds them. The commonest of these butterflies, known simply as the “caper white” (Belenois java - see photo at right) is a strongly migratory butterfly, often very conspicuous for its large numbers spread over hundreds of square kilometres, in early summer. The reasons for this migratory habit are not known, but may simply be the result of overpopulation in the area they are leaving. The other four species are very similar in appearance, and all are frequently seen together.
The caterpillars often infest their host plants to the extent of eating off every leaf and all the new shoots as well. The result would be not pretty, except for the beauty of the fluttering host surrounding the plant. The caper trees are used to it and bear it all stoically, bouncing back after every season with the renewed freshness of a plant that’s been skilfully pruned. One of the host plants, the caper relative called broombush (Apophyllum anomalum) saves time by being leafless in the first place.
The Caper White butterflies are a favourite food of Blue Wrens - another good reason for growing Bumble trees. The dense and sometimes prickly canopies of the tree capers are favourite nesting sites for a number of small birds.
We have five local caper species. Three of them are small trees ( and Capparis arborea, C. loranthifoliaC. mitchellii). Then there are their relatives, the prickly little bumble-bush (C. sarmentosa) and a scrambling shrub of the Darling Downs called “split jack” (C. lasiantha). They all have lovely white flowers, which, with their four petals, resemble butterflies themselves.

Fruit formation is a curious process. The dying flower puts out a fruit “stalk” from its centre, as though it’s holding its fruit away from it, at arm’s length.

All the species are very prickly when young, with the characteristic paired spines situated where the leaf-stalks meet the stems. The juvenile leaves are very different from the adult ones, so it is difficult to identify this little plant (at right). It grows tucked up next to the trunk of a scrub wilga, in Franke Scrub near Highfields, where there three different Capparis possibilities.
They lose their prickles to a varying extent as they age. The little C. sarmentosa never loses them, and at the other end of the spectrum, the silvery-leaved tree from the eastern slopes of the Range, C. loranthifolia, can be completely prickle-free when it’s mature.
Capparis mitchellii is the best tree for the blacksoil, and other alkaline to neutral soils. Its range overlaps with C. arborea, on the edges of our redsoil. All the local native capers are very drought resistant, but C. mitchelli is the best for frost resistance.
The capers you buy in little bottles in the supermarket are the flower-buds, pickled, of Capparis spinosa, a shrub native to the Mediterranean region. There seems to be no reason why buds of our native species couldn’t be used for the same purpose. If you like capers - go for it! (But do plant your own trees if you want to do it in any quantity. Australia is long past the stage where wild harvesting of bush tucker can be considered ethically respectable.)

Thursday, November 27, 2008

Austral Cornflower

Rhaponticum australe (Stemmacantha australe)
I was astonished to hear that this rare and threatened plant had been found growing on a neglected block in Toowoomba a few years ago. It must have been the last city refuge for this plant, though it would once have been common here. It used to be found on our local red ridges and blacksoils, wherever those very common local trees, mountain coolibah (Eucalyptus orgadophylla) and narrow-leafed ironbarks (E. crebra), are found. In town, gardeners usually mistake it for some kind of milk thistle, and weed it out. In the country, the livestock have done the job instead. So plants growing wild are now very rare indeed.

It is one of those native plants which you’d have to classify as “almost ornamental”. Planted in quantity their spring flowers do make a rather attractive garden statement, with their globe-artichoke-like heads.

Their light brown seedheads have an almost animal appeal. I find myself wanting to pat them on the head like little lambs.
In fine weather, the seedheads are long-lasting. However,  they don’t stand up well to rain and wind, and soon look messy in poor weather. A firm hand with the secateurs is needed to keep the garden looking pretty.

A few heads should always be saved for seed, of course, and they’re easy to reproduce this way.

For those who have enough land to be able to afford some “rough”, this is a good plant to naturalise there, as it provides food for little birds and herbivores.

Stout Bamboo Grass

Austrostipa ramosissima
This is an ornamental grass which grows along the slopes of Great Dividing Range in the Toowoomba region, on red soil.
 It makes an excellent quick hedge, with the plants lasting about three years before they get shabby. Removing the old plants is simple, as they are shallow-rooted clumps. If done in spring, this allows self sown seedlings to grow up i their places. (Older plants lose their vigour if they are cut back at all, so rather than making any attempt to refresh them by cutting them back, it is better to remove and replace them.)

Like so many of our lovely Australian plants, this one is more highly valued as an ornamental garden plant overseas, than in it's home country. In the US, it is known by the delightfully appropriate name of "Pillar of Smoke".
It is frost and drought tolerant.
I find it problem-free, despite its self-seeding habit. Unwanted seedlings are easily removed by hand or killed by mowing.
Like all native grasses, it is an environmentally friendly thing to grow, providing food for small birds and insects, and shelter for small animals.

The tall stems, with their generous spring panicles of very fine seeds are also rather good in a vase. A few Christmases ago, when I was feeling rather arty (and had no grandchildren to amuse) I used a few stems of this grass for a Christmas tree. I decorated it with Christmas earrings and tiny baubles, and was rather pleased with the result!

Saturday, November 22, 2008

Native or Not?

Papaver aculeatum
I was delighted, a few weeks ago, to find a “native poppy” growing beside the Mt. Kiangarow track at the Bunya Mountains.
I had not previously found it growing on a relatively unmodified site on basalt soil, so was pleased to find out that it seemed to be a genuine local.
Alas, my subsequent research revealed that this may not be so!
Trawling the internet, I found a very good article by Tony Bean, of the Queensland Herbarium, on his new system for deciding the probable status of plants, like this one, whose origin is disputed. He puts together a very convincing case that our “native” poppy is native in South Africa only.
I have been happily growing it in my garden for years, and will go on growing it. Actually, it would be difficult to stop growing it, as it reseeds itself every year. I’m happy for this to happen, as it is an attractive plant whose spring flowers add a touch of an unusual shade of scarlet to the garden
But I’m disappointed.

Yellow Marshwort

Nymphoides crenata
What a silly little plant this is! It doesn’t like the container I’ve put it in. It’s too shallow for it, and there’s not room for a good layer of deep, rich mud, which is what it would really like. So it has responded by shrinking its leaves, as it does in the wild when times are tough. It seems to be telling me what a mean old gardener I am.
So I didn’t expect it to flower so happily, with normal-sized flowers which are bigger than the leaves.
In better conditions - still (or slow-flowing) fresh water to 1.5m deep, with a muddy bottom - the leaves are about 12cm long.
This plant dies back to almost nothing in winter. Fresh new growth appears every spring, and spreads across the water by stolons (like those on strawberry plants). Flushes of flowers appear every few days from November to about May.
Like strawberry plants, they are easily reproduced from the plantlets which appear at each node.
This wavy-leafed marshwort is plant of the inland, but is now often seen east of the dividing range, having been introduced there by gardeners. Apparently they like the wavy-edged leaves of our sort rather than the smooth-edged ones of their local native, the very similar Nymphoides geminata.

Sunday, November 16, 2008

Who’s been eating my Mosquitos?

Yellow Bladderwort  
Utricularia gibba ssp exoleta (Utricularia exoleta)
A little bird gave me some of these lovely plants for Christmas. Literally.
They appeared in the Gardner pond one year.
For some time, I paid no attention to the plant, which was just a mass of fine, entangled green stems, with no obvious beginning or end, top or bottom, roots or leaves. It was peppered with little black lumps, smaller than a pinhead, and floated submerged, neither very attractive, nor particularly unattractive. When the first flowers appeared in a shallow corner I was slow to connect them with the floating plant.
They were very pretty, bright yellow, measuring a centimetre across, and standing 6cm above the water on fine little stems. I was charmed by them, but had considerable difficulty making an identification. When I eventually discovered what the plants were, I was delighted to know that this is one of the world’s more sophisticated carnivorous plants!
The “black lumps” were the bladders, which provide the plant with enough nutrients for it to be able to live in quite nutrient-poor water. I’ve discovered that they are very effective at keeping my bowls of water-plants free from mosquito larvae. They don’t get rid of visible wrigglers, but water with this plant in it remains wriggler-free, so it must be consuming them fresh out of their eggs.
Some research told me that the bladders in “hunting” mode are rather flat, with a little round entrance above which a few trigger hairs protrude. Nearby glands secrete a sugary bait. If a tiny creature touches the hairs, the bladder springs into its full ball-shape sucking in water and the prey. The door snaps shut, and the water in the bladder is pumped out again through some little glands (taking 30 minutes to 2 hours). By then, the bladder has returned to the flattened shape, and opens its door for more prey.
Meanwhile, the previously-caught prey is slowly being digested to feed the plant. Bladders which have fed successfully are black, and I notice that my plants’ bladders don’t have much luck in winter, when I suppose the bladderworts have to live on photosynthesis alone.
Apparently mosquito larvae and even fish fry can be captured by the larger bladderworts – and the little dots on my plants seem to be large by bladderwort standards. They don’t seem to bother the goldfish or frogs. (I have no native fish, so don’t know whether these are affected.)
Although these bladderworts can live in fresh, still water of any depth, they need shallow water to flower. The water’s pH should be 6.3 to 6.8 - rainwater is fine. A ledge at the edge of a pond, or a dish or bowl part-filled with soil or sand seems to suit them, and a warm, sunny site (they like to be between 18 and 29°) keeps them flowering well, but they survive the winter so long as their water doesn’t freeze.

How to “Source” Bladderworts.

Acquiring some for yourself may be a simple matter of providing a suitable habitat, and waiting for the birds to provide. I have a rather large birdbath, in which I’ve put some sandy soil which slopes from just above water level to 5cm deep, so plants can choose their own depth.
Other gifts from the birds have taken root on the higher soil, making a healthy little ecosystem and a very pretty garden picture. Magpies bathe in the deeper water, but this doesn’t worry any of the plants in my pretty dish-full.

Other Gifts from the birds.
We have never been able to stop the drips from the solar hot water system on our roof. The people from Solarhart assure us this is normal. I hate letting it go to waste, though, so have a birdbath/water garden underneath it, which I only need to top up with rainwater in very dry weather.
It now has four lovely thing growing in it, all bird-given.
Triangular Club-rush, Schoenoplectus mucronatu
This elegant “decorator” plant it is so good to cut for a vase when it’s in flower (Sep - May). The light green triangular stems can get to 50cm high, but are much less in the restricted soil of my bird-bath. 2cm from their tips they put out - sideways - a neat bunch of their little flowerheads - the golden-brown cone-like “clubs” which give them their name.
Left to themselves in a pond or dam they form a thicket in the shallow water and provide good breeding sites for frogs. Though they seed freely, they are not particularly invasive. In my own dish, I find a once-a-year (early spring) clean-out and re-plant keeps the arrangement looking good year-round.

Trailing Pratia, Lobelia pedunculata (Pratia pedunculata)
I am unsure whether this plant came to me from a native source, or from a garden, as I am not aware of it as a wild plant in the area.  It as it is an easy native plant to buy, and mine is a lovely (commercially desirable) shade of blue, so perhpas it's not a real native. On the other hand, water plants tend to have a very wide native range, so perhaps it can qualify as a valid addition to this blog about local native plants..
The plant needs constant dampness for success in full sun, and rewards us for providing it with a generous sprinkle of its blue flowers from October through to April.
It’s said to tolerate light frosts.

Small-leaved Pennywort, Hydrocotyle peduncularis
You see this one on lists of plants recommended for frog-gardens. It has dainty little (1cm) leaves, almost circular, with five scalloped lobes. They make a pretty carpet of soft, fresh green at the water’s edge (both in and out of the water), and mix happily with other small plants such as Lobelia and Utricularia.

Friday, November 7, 2008

Plover Daisy

Leiocarpa brevicompta (Ixiolaena brevicompta)
I have no idea why this plant is called “plover daisy”. Perhaps it’s because spurwing plover (also called masked lapwings) nest amongst the plants. I’m sure we all know this common local bird, which nests on the ground, and defends it vigorously by dive-bombing us and shouting “ack-ack-ack... “
It’s a pleasing mental image, the yellow masks of the plover among the soft, woolly blue-green leaves and the yellow flowers of its namesake daisy.
This is a rather variable plant, with Australia’s best version, having the most generously woolly foliage and the largest buttons, occurring naturally on blacksoil in a strip between Drayton and Cambooya. It occurs in other parts of our area, but so those wishing to grow it might prefer to source their plants from the right spot.
Like the prophet, it is little valued in its own country, and we rarely see this plant in gardens despite its obvious desirability. It is particularly good with a cottage-style garden and has that style’s traditional easy-care qualities, being a frost and drought-hardy biennial, very easily grown from seed. The plants are easy to find at present as it is now showily in flower around the district. Once established it self-seeds fairly easily (particularly if the garden gets a little cultivation and water), the seedlings appearing in spring. It would be very suitable for sale in punnets, as a bedding annual
Self-sown plants have growth spurts in spring and autumn and look their best if cut back twice a year to keeps the plants neatly shaped, and encourage regrowth of the woolly blue-green foliage.
A warning to graziers is appropriate, however. Though this is a useful fodder plant before it flowers, its seeds can poison sheep. The Queensland Dept. Of Primary Industries has noted that there have been deaths from this cause in Western Queensland when the plant is eaten in problem quantities, (which they define as 50% or more of the total diet, for 1-2 weeks). They suggest these management strategies:
I. Stock pastures heavily while the plant is still green, to reduce seed-set.
2. After seeds appear, let each mob of sheep graze on the pasture for a week only, once the seedheads mature, then replacing them with a different mob. Apparently the sheep actively seek out the seedheads to eat, and DPI regards this as a safe way of reducing seed numbers.
Based on this, I consider that this is not a plant we need to avoid for fear of causing a poisoning disaster.
Where we see it naturally occurring in pastures here, the proportion is always relatively small and does not seem to become dominant even with overstocking - though perhaps others may report a different experience? The seeds are not wind dispersed, and self-seeding in my garden has only ever occurred very close to the parent plants.
Too many good native plants are avoided, with the potential to slide quietly into extinction, because they have been discovered to be toxic to stock. The word gets around that they are poisonous, and people tell each other not to grow them without first establishing to what degree they are really likely to be a problem. That stock feeds mainly on Australian plants means that they have (rightly) been the subject of much research and some publicity. Meanwhile, many very commonly grown introduced plants, some of them really dangerous to children, appear in our gardens without comment.

Wednesday, October 29, 2008

A Valiant Warrior

Xanthorrhoea species
When it comes to attack by fire, grasstrees are experts at defence. This fellow has been through quite a battle, as you see, but was still carrying his spear!
Note the little tuft of green on his crown - he’ll be as beautiful as ever in a year or so - perhaps even more beautiful. The blackened trunk which grasstrees acquire after burning enhances their good looks.
There is a story that burning causes them to grow more quickly. Someone I know tried it, and decided it made no difference, so I’m not prepared to take any risks in my backyard.
There is also a story that grasstrees grow extremely slowly - just an inch every hundred years. I’ve had less faith in the theory since I discovered that it was based on a specimen growing in the Edinburgh botanic gardens - hardly the ideal climate for finding out the optimum growth rate of one of our local plants!
These specimens photographed in a railway cutting near Benarkin had obviously been born after 1913, as they were growing on the cut faces, and that is the date that the railway was built. You can see that they have been growing at a good speed, despite the complete absence of any care from a gardener, since then.
You might recognise the plants in the photo below, which can be seen from a walking track in the Bunya mountains. We now think of this sort of rocky hillside environment as being typical for all grasstrees - and indeed it is, for some species.
These plants at the Bunya Mountains are the “white grasstree” Xanthorrhoea glauca. Unusually,  species is also very much at home on the blacksoil plains, something which surprised the explorer-botanist Ludwig Leichhardt.
Sadly, as with most of the native plants which grew on this prime agricultural land, few specimens remain in this habitat, but the knowledge that they grew there is useful to us, when choosing plants for a black soil garden. This is the species to use.

Thursday, October 23, 2008

Native Spinach

Tetragonia tetragonioides
Family: AIZOACEAEThis is a fast-growing, prostrate annual plant which grows very easily from the hard, prickly seeds. It is quite likely just to come up in your garden, as it did in mine, brought by birds, no doubt. It is a nutritious and tasty no-cost vegetable, which, once established provides leafy greens for much of the year with no further help from the gardener. It’s worth putting aside a well-composted space in the vege garden, one or two metres square, for it to ramble and reseed at will. It appreciates a bit of water in very dry times, but doesn’t really need it.
Discovered in 1770 by the botanists on Captain Cooks’ famous voyage, this plant was named by them “New Zealand Spinach”. After leaving New Zealand, they sailed to Australia, and found the same plant growing here. Cook was one of the first sea captains to recognise the scientific discovery that, scurvy was caused by a lack of something - now known to be vitamin C - in fresh fruits and vegetables. The value of this plant as a health food was quickly recognised. The officers tried it and pronounced it “as good as spinage”. (The knowledge that they enjoyed it with a dish of stingray tripe does, I’ll admit, reduce one’s confidence in their taste.) They carried the seeds back to England where it became what is still a popular summer vegetable. Known there as “tetragon”, it is considered to have a flavour superior to spinach and silver beet.
HOWEVER, we do need to bear in mind that, as with all leafy green veges, the right time to eat it is before it flowers. Unless they are being grown for seed, older plants should be weeded out.
Twenty years later, the first white settlers at Sydney Cove were having trouble finding enough food to stay alive. Saturdays were set aside for collecting native plants to eat, especially those which could prevent scurvy. Tetragon was one of the plants collected. It lost favour early on, however. In a colony nostalgic for the homeland, the prejudice in favour of “real English spinach” couldn’t admit that a “weed” from the bush might taste better!
The modern bushfood industry calls this plant “Warrigul Greens”.
Leaves should be washed, chopped (or roll them up and slice them finely), and lightly cooked. Butter, salt and pepper is all that’s needed for a delicious vegetable, but native spinach is also good added to a creamy pasta sauce, included in a risotto, or cooked into a quiche. Another recipe serves it in a white sauce with chopped boiled egg and nutmeg. An imaginative cook will have no trouble finding a good many ways to serve this versatile vegetable!
There have been some concerns about the safety of this plant because it contains oxalic acid, which can be harmful to humans.

How dangerous is Oxalic Acid?A number of Australian plants with edible leaves have high oxalic acid levels, and are avoided for this reason. Taken in excess, oxalates are poisonous substances which can cause nausea, vomiting, corrosion of the digestive tract, and sometimes, death. Frequent use can also cause calcium deficiency and kidney stones.
However, to put the issue into proportion, we should bear in mind that oxalic acid occurs in all green leaves, and that we already eat a lot of plants that are high in it.
The amount contained in native spinach is approximately the same as in “English” spinach, and a little less than in silver beet. Once plants start flowering the oxalate levels in their leaves increase, which is why native spinach (like most of the other leafy greens that we eat as vegetables) is best not eaten after this stage.
Many of the everyday herbs which we grow, or buy in the supermarket, are very high in it. French cooks couldn’t manage without a pot of sorrel (Rumex acetosa), which an internet sales source describes as having “a lemony tang that’s almost as sour as rhubarb”. It’s the high level of oxalic acid that provides the sourness.
It actually takes quite a lot of it to cause harm. Ill effects are typically found only when consumption is very high (more than 12 cups of cooked leaves a week). This is the sort of consumption which occurs in poor, third-world communities where a belly-filling feed is hard to come by.
Some writers claim that high-oxalate vegetables should only be eaten after a cooking process involving blanching them in boiling water for a minute - and this is certainly a way to make them safe, if you think you might be feeding the family too much of it. Most of the oxalates dissolve easily into the water, which is then discarded. Others consider that a certain amount can be eaten safely in recipes where no cooking water is discarded, and salads. The popular spinach quiche would be an example of a relatively high-oxalate meal often eaten in Australia.
A diet high in oxalate-rich leaves should also include high calcium intake, which may offset the tendency to form kidney stones. Typical recipes involve milk, yoghurt, or cheese.

Thursday, October 16, 2008

Necklace Pod

Sophora fraseri
The necklace pods, are flowering beautifully this year, no doubt appreciating the extra rain they had earlier on.
This is a pretty, waist-high shrub with soft silver-green "ferny" foliage and spikes of yellow pea-flowers.
The common name refers to the seed-pods, which fit snugly around the seeds, giving the impression of a string of up to seven beads.
It typically grows on the drier edges of hoop pine vine forests, particularly on basalt ridges. Once common, it has become rare with the clearing of its habitat, and is now listed as a “vulnerable”, plant. You can still find it growing wild on the ridges in the Kingsthorpe area.
It’s a very drought hardy plant (this one in my garden has never been watered), but does grow better in wetter years, and looks more splendid than this if the grower can afford to water it well.
It makes a lovely show if grown with the type 2 darling pea (see article below), as they flower together, and the pink peas fill in below the yellow ones of the necklace pod.

Thursday, October 9, 2008

Who’d Grow Nettles?

Urtica incisa
There are a lot of good reasons for growing this antisocial plant. One is that it is the only host plant for this pretty butterfly, which is an Australian Admiral. When they rest with their wings up, these butterflies are not very conspicuous. This one which I found in my garden last week, wanted to bask in the sun, and did it long enough for me to get this photo. I wondered where it had lived, as a child.
I learned of another good reason for growing nettles from George, on a Toowoomba Society for Growing Australian Plants outing a few years ago.
George was insisting that stinging nettles were a Good Thing in compost heaps, but was a bit vague about the details, so I looked it up on the internet, and found that many people agree with him. Some put the leaves in their compost heaps, or make a compost starter by putting leaves and water in their blenders, then pouring it straight on the heap. There seems to be no general agreement as to whether the effect - speeding up the composting process -is due simply to the high nitrogen content of the leaves, or to some other ingredient.
Meanwhile, other people prefer to apply the goodness of the nettles straight to the garden. The TV show Gardening Australia provided this recipe:
Stinging Nettle Tonic: This plant is high in nitrogen so it promotes good leafy growth. Roughly chop up 1.5 kgs of stinging nettle and then add 4.5 litres of water. In a week or so this mixture will have started to ferment. The liquid can then be used diluted or undiluted as a foliar spray.
That’s two reasons. Here are some more:
3. The roots make a good yellow dye for cloth. Nettle roots were traditionally used in Russia for dying Easter eggs. They wouldn’t have been using our Australian species, of course, but the results are likely to be similar.
4. Nettles have been used as a material to weave into cloth. We’re not talking about any rough old cloth, either! Apparently is it quite silky, and makes better “velvet” than cotton does. It’s also used to make fishing nets, ropes and paper.
5. The tiny seeds can be crushes for their oil, which has been used in lamps.
6. It has some medicinal uses. Curiously, the custom of whipping oneself with nettle leaves was part of folk medicine both in Europe and in aboriginal Australia. The anti-inflammatory effect is supported by modern research, but can be more agreeably absorbed by drinking a tea made from the leaves (which are also high in rich in vitamins A, C, D, iron, potassium, manganese, and calcium..
7. And you can cook it as a healthy vegetable, high in vitamins A, C, D, iron, potassium, manganese, and calcium. Only leaves from the young plants should be eaten. Once the plant has flowered, some substances which irritate the urinary tract develop in the leaves (which probably give the plant its reputation as a powerful diuretic). Apparently it also contains serotonin, that substance which helps us to feel happy. (Serotonin is also found in chocolate, and is supposed to be the source of those chocolate cravings. Eat nettles, and do away with those unhealthy cravings!) The cooking kills the sting, and nettles can be eaten like spinach, or in soup. Try it in a recipe using potato, chicken stock, salt, black pepper, and sour cream.
Not to be confused with the very similar-looking introduced annual nettle Urtica urens, (not actually found in our area, so far as I know) the native nettle Urtica incisa has stems which die back to a perennial rootstock each winter. Growing naturally, they are an indicator of rich soil, so if you’re considering buying a block of land and notice nettles on it, you can buy with confidence knowing that it will be a good place to make a garden.
So those are the reasons for growing nettles.
Of course there is just one reason for not growing it...