Saturday, August 28, 2010

Knowing the Fruits

Acronychia oblongifolia
I am often frustrated, while walking in rainforests, by finding fruits on the ground and wondering what they are. Peering up at the canopy may prove futile, as I am unable to see where the fruits have come from. A tree? A vine? And even if I can see it, is it possible to identify the plant?
However, when I came across a generous scatter of these distinctive white fruits on the path in the Goomburra section of the Main Range National Park two weeks ago, I did recognise them, and could therefore easily find their mother plant. They are the fruits of the “common acronychia” or “white aspen”, a plant which is becoming well-known as a “bush tucker” plant. The fruits are edible but very acid, and people make a fruity drink out of them, adding loads of sugar to make it palatable. They also use them in jam, ice-cream, and cakes, as well as seafood and chicken dishes. The very simplest culinary use for the fruits is to add just one or two to a jug of water to give it a nice tang - rather like the restaurant custom of adding slice of lemon.
Alternatively, they can be left on the plant for the birds.
Acronychia are interesting plants in that they are “unifoliate”. This means that their shiny, aromatic leaves look, at first glance, like simple leaves - but close examination shows a join between the leaf and its stalk (petiole). It’s as though a leaflet decided to get together with others to make a compound leaf - but failed to persuade anyone to join in.
Introduced citrus trees have the same unifoliate arrangement.
The late summer flowers are amazingly beautiful. They are white, with four petals, just 1cm across. Their complex geometrical design just asks to be used as an art motif. They are rich in nectar and attract butterflies, and the plant itself is a host for our largest local native butterfly, the “orchard” butterfly.
The plants are likely to be affected by both drought and frost - yet can easily be grown in the Toowoomba district in a sheltered spot, only needing extra watering to get established, and perhaps in the heaviest droughts. They can be grown as shrubs (with pruning to restrict their size and make them produce multiple stems) or as small to medium-sized shady trees, suitable for suburban gardens.
We find common Acronychias along the range from the Bunya Mountains, via Ravensbourne and Goomburra, to the New South Wales border. They may once have grown in Toowoomba, but the vegetation of our fair city’s once rich range-side has been so radically “modified” that it is now impossible to know

Thursday, August 19, 2010

What would we do without Wattles?

Acacia decora

Just as we begin to feel that winter is going to last forever, and we really can’t stand it any more, out they come in a blaze of glorious colour, reminding us that the cold, dry wind is indeed going to stop blowing in just a few more weeks time, and spring is truly on the way.
Their perfume is therapy in itself.
This particular plant was abuzz with honeybees, native bees, and little beetles, all after the dusting of pollen which covers the flowers.
The species is called “Pretty Wattle”, and I think it is one of the best wattles for gardens.
It is a drought-hardy, frost-hardy plant, and (unusually for a wattle which flowers spectacularly), it is long-lived.

Plants in the wild usually have two or three trunks, which are never more than approx 10cm diameter. They are said to respond well to coppicing, and I have grown this particular plant to try it out on. Once it has finished flowering it’s for the chop, as I’d like to see whether I can persuade it to be more shrub-like, with multiple stems.

Note that its branchlets are yellow. In this, it differs from the red-twigged form of A. decora which grows on sandstone soil, down Stanthorpe way. This plant is from seed taken just west of Toowoomba, on black soil.
Acacia decora is sometimes available in commercial nurseries, in the red-twigged form, but I prefer to grow the local variety - and would particularly recommend this one to anyone wanting a good wattle for black soil, as I think you could expect a longer life from this plant which is adapted to local conditions.

Friday, August 13, 2010

Red Kennedy Pea

Kennedia rubicunda
August - September is flowering time for this pretty climber - and the flowers are appreciated by little honeyeaters.
It’s a plant that some hesitate to grow because of its reputation for being rather too vigorous, swallowing shed-sized buildings whole. Perhaps it does indeed grow like this in well-watered sites, but I have found that in a situation where it receives no supplementary watering it would restrict itself to a trellis 2-3 metres square.
I cut mine back each year after flowering, to a network of major stems, to ensure that its new leaves are well-distributed, rather than restricting themselves to the top of the trellis.
In the wild, these are among the first plants to regrow from seed after bushfires. They grow on most kinds of soil, including heavy clay.
Mine is in a frost-free situation under eaves. Frost is said to cut them back. Although they regrow from the root, a winter cut-back would prevent a year’s worth of flowers, so the plants are best grown where this wouldn’t happen to them.

Friday, August 6, 2010

Ellangowan Turkey Bush

Eremophila deserti

Eremophilas, otherwise known as “emu bushes”, “turkey bushes”, “poverty bushes”, or even “fuschia bushes”, are deservedly popular Australian native plants. Their name, “eremophila”, means “desert-lover”, and they are indeed all very drought-hardy plants. Many have beautiful flowers in red, pink, white, yellow, or blue.

There are about 215 species of eremophila, and they have become popular in gardens here over the last 20 years. They grow particularly well on the alkaline soils west of Toowoomba.
Few of them are actually native to our own region. Here is one that is - though it’s also widespread over most of inland Australia. It is named after a local town on the Condamine River, and has comparatively modest little flowers so is rarely if ever seen in gardens. It does flower plentifully, though, and the fruits which follow are very popular with birds, so it is well worth growing. It would make a particularly good low hedge, flowering sweetly in winter, and making itself useful because of its “fire-retardant” tendency. (No, it won’t stop a big bushfire - but it won’t add to your problems by being highly flammable, either.)

It is also frost hardy.

These photographs were taken at Irongate two weeks ago.
You can see that it naturally forms a dense, rounded bush. Older plants get leggy, so optimum long-term management in a garden would probably include pruning - but not until the birds have had a chance to feast on the fruits. Where it is eaten by stock, it has shown that it coppices well.

Too Poisonous for Us?
Eremophila deserti is also known as “Ellangowan Poison Bush”.
Give a plant a bad name, and people, rather naturally, lose all desire to grow it!
Yet the its toxic effects have been restricted to stock which feed on its leaves - and are about equal to those of lantana. Most of the other eremophilas are probably also as toxic.
As with all these plants, “animals grazing quietly in the field eat the plant readily and apparently without ill effect” (Everist 1947). “Almost all recorded field cases of poisoning have been sheep and cattle travelling on stock routes” (Everist again). Animals in these conditions often succumb to poisoning from plants of many species which otherwise do them no harm. Droving leaves them tired, stressed, and hungry. They are often forced by hunger to eat plants which they would otherwise ignore, as all the more palatable feed has been eaten out by preceding stock. While of concern to drovers, the poisonous nature of Ellangowan turkey bush doesn’t seem to be something that need worry gardeners.