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.)