Thursday, October 22, 2009

Sandpaper Fig

Ficus coronata
Figs are plants with very strange habits. Their flowers form INSIDE the young fruiting bodies, and are pollinated by wasps which enter by the tiny hole in the end. The “fruits” we eat may still be flowering inside. And yes, the wasps are always there. They're minute and fig-flavoured, so we never even notice that we are eating them.

This two-year-old  Ficus coronata in Peacehaven Botanic Park has put out a great old crop of fruit. You can see that it’s almost leafless. The species drops most or all of its leaves in early spring. (The leafless, fruiting branches do make a decorative feature in a flower arrangement.)

Ficus coronata also has the strange habit called “cauliflory”, where fruits pop straight out of the large branches and even the trunks, as in this photo I took a few weeks ago in the Brisbane Botanic Gardens.
(I have heard a rumour that Grapetree Road, near Pechey, was named for a plant with the cauliflorous habit. Does anyone know what the “grapetree” was? Please leave me a comment, below, if you do.)
This is the best native fig for garden purposes. Unlike the rainforest giants, the little sandpaper figs don’t have those enormous water-seeking roots (though it is still best to plant them five metres away from your pipes, paths, and foundations).
It makes a bushy little tree if grown in the sun. If it does get straggly, it’s easy enough to prune to shape, and can be kept to large-shrub-size.
Although these plants are most often found in creek beds in the wild, they are drought hardy trees which grow well (like specimen below) in unwatered local gardens.

Plants can be dioecious (separate male and female trees) or monoecious (male and female flowers on the same tree), so to be sure of getting fruits, it is best to plant several of them. They can be planted close together, (40-50cm apart) to save space. After Christmas, the fruits ripen to this pretty shade of red.
All native figs are valuable food sources for birds, fruit bats, and possums. People also eat them, and those of Ficus coronata are said to be the best-tasting Australian fig.
Eaten raw , they have an quite acceptable flavour, though they can be a bit dry if they come from a drought-stressed tree. Rub the hairs off before putting them in your mouth! The fruits can also be used in cooking, or crystallised.
They are rather variable from crop to crop, even on the same tree, so if one lot is disappointing, have faith! Watering well as the trees are fruiting, and fertilising early in spring, are two ways to improve the crop.
And yes, you really can use the leaves as fine sandpaper!

Thursday, October 15, 2009

Native Frangipani

Hymenosporum flavum
This is a very familiar small tree in local gardens, being one of the few natives that have “crossed over” into mainstream gardening.
It’s a small tree, no relation at all to the chunky-stemmed introduced "Frangipani" (Plumeria species) - but its flowers have a similar strong fragrance. As you will notice from the plant's family name, this tree is really a kind of Pittosporum.The family is worth exploring for other species, if you're looking for fragrant shrubs or small trees for a garden.
These flowers are unusual, with their flecks of red. I photographed them a few weeks ago while bushwalking north-east of Crows Nest.

The more usual flower is creamy-white when new, and ages to deep yellow, like those on this two-year-old specimen in Peacehaven Botanic park.
Well-watered specimens tend to grow fast, but need pruning to prevent legginess, while specimens that have "done it tough" bush up attractively without further attention. Grown in full sun they make a well-shaped ornamental tree. In the shade between buildings, they make a tall slender trunk with no branches, and the narrow crown peeping just above roof height.
They are claimed to be somewhat fire-retardant, so are a good choice for gardens where this might be a worry.

Thursday, October 8, 2009

Black Orchid

Cymbidium canaliculatum
Bushwalkers always find something to delight them. This magnificent black orchid was flowering its heart out in a dead ironbark tree last week. No doubt the tree had a big long hollow, which accommodated the plant’s enormous root system. More roots, had clearly formed since the tree’s death, as they were between the timber and the bark. The bark was peeling off, so the orchid will have to retrench a little when it goes.
I hope the orchid goes on in good health for many years though. There are good reasons for leaving hollow dead trees where they stand. The feather glider, which popped out while we were admiring the orchid, is another.
Ironbark timber is so strong that a dead one can stand for hundred years or more, still doing its bit for the ecology.
This lovely plant is Australia’s most drought-hardy orchid, and is common in the bush in our district. It‘s a plant of the inland, unusual in preferring to grow well away from the rainforests and vine scrubs which are the preferred habitat of most orchids.
It usually grows in hollow eucalypt trees, where the rhizomes ramble through the dark tunnels and rotten heartwood, and pop out leaves wherever opportunities arise. “Plants” which seem far apart - like the three in a Eucalyptus tereticornis not far from this specimen - may well all be part of the same plant. A large old specimen can have roots 10 metres long.
The name “canaliculatum” refers to the channel-shaped leaves, which direct rainwater and dew towards centre of the plant. This is part of the secret of the plant's drought hardiness. The other part is the huge root system, protected from dehydration in its well-insulated, deep tunnels. Orchids are usually regarded as acid-loving plants, so the discovery that the ends of the roots of big, old plants like this are actually in very alkaline conditions (pH 9!) is somewhat startling.
Black orchids often grow in exposed places well away from the shelter of any trees, and have even been known to establish themselves in fence posts. They are said to prefer a north-east aspect, but are certainly seen thriving in other positions.
Orchid enthusiasts from our coastal cities regard this as a rather difficult orchid to grow. It is uncomfortable in the humidity. We have an advantage over our coastal friends there, but it is very rare indeed to see a cultivated specimen as magnificent as this. It’s difficult to give it the conditions it really prefers!
These orchids - like many other of our native orchids - are easily killed by root disturbance, so trying to take an established plant like this home is most likely to kill it. Orchid “collecting” is usually just another name for vandalism - and of course, taking plants from the wild is illegal, unethical, and much resented by bushwalkers and other genuine lovers of Australia’s wild plants.

Native Bluebells

Wahlenbergia (stricta?)
Here is a lovely stand of native bluebells, which I photographed last week in “Glenvale Gardens”, a retirement village in Toowoomba. Apparently the garden won a prize in the Carnival of Flowers, and I’m not surprised at that.
The surprise was that locally native flowers were used in a local flower garden - something I’d love to see more often.
I didn’t ask, but I expect the flowers were Wahlenbergia stricta (white backs on the bells).

It is a common plant of our grasslands, often seen on our road verges around here where it takes advantage of the rainfall runoff provided by the road. It’s a perennial, which dies back in winter, to reappear in full beauty in spring.
Individual plants are rather sparse, so they are shown off at their sky-blue best if they are grouped, as these ones are. These are frost hardy, drought-hardy plants, which like to be in full sun.
I just wish they were easier to buy. If they were, I’m sure we’d see more of them on our local gardens.

Thursday, October 1, 2009

Peacehaven Botanic Park.

I went wandering in this park again this week, and had the pleasure of running into Robert Campbell (Toowoomba Regional Council, Parks and Gardens Highfields), who is responsible for the planting and maintenance of this remarkable botanic garden.

Aphananthe philippensis

A dense plant which might prove to be good for hedging.

I found out that the park is younger than I thought, with these local native trees being only two years olds I am very impressed!
Robert tells me they have not been watered since they were planted. He credits the fast growth to the large hole which he digs for each one. (I gathered, from the general hand-waving, that these holes were about a metre across, and something approaching the same depth.) He scatters some slow release native fertiliser in with the soil as it is replaced, puts on a deep layer of course forest mulch, and the results speak for themselves!

Acronychia laevis

An ornamental plant with unusual blue and pink fruits

A garden full of plants of local provenance is something that hasn’t been done here before. We Toowoomba people are so used to having access only to “native” plants which have been brought in from elsewhere. Plants from local sources are now available, but haven’t made much impact, yet, on the local gardening scene. Robert did point out to me that much of the credit for Peacehaven’s ability to display this special range of plants is due to Steve Plant, (Natural Resource Management Field Officer TRC Northern Region) who has done some groundbreaking work in establishing the community nursery at Crows Nest. There, Steve grows local plants from local seed, and this is what Robert is growing at Peacehaven.

Clerodendrum tomentosum
A plant that stands out twice a year. In spring it has these perfumed flowers, then in summer it has very ornamental fruits.

It is really quite exciting to have something, in our own district, which is following the grand old tradition of botanic gardens - doing useful work in trialling plants. Our great Australian botanic gardens were established, like their overseas counterparts, to trial exotic plants. Their successes have become the staples of traditional Australian gardening.

These neat, permanent plant labels were sponsored by individuals and community groups, in a project organised by the Friends of Peacehaven, a group which meets there on Thursday mornings.

Meanwhile, Australian plants were being trialled overseas with enthusiasm, beginning when Captain Cook’s voyage arrived home with its collection of specimens. Much of our initial knowledge about how to grow our own natives was discovered overseas. Successful eucalyptus oil, and cut flower industries using Australian species, were established in faraway countries as a result of research done there. Australian plants were used in gardens in Britain and Europe long before they became popular here.

Elaeocarpus kirtonii
A tree from the Bunya Mountains

As a nation we have recently come the full circle, with our modern botanic gardens trialling Australian plants for use in Australian gardens.
And now, in our own district, we have a place where we can see our own local native plants in a public garden setting, all neatly labelled so we know just what we’re looking at.
They do impress! These are clearly good garden plants.
How to find Peacehaven: If coming from Toowoomba, turn left at the first Highfields traffic light, into Cawdor Road. Take the third turn on the right, into Kuhl’s Road. (Stan Kuhl was the man whose general bequest of the land, to Crows Nest Shire Council, made the park possible.) Peacehaven Botanic Park is on the left, just a little way along.

Bitterbark Tree

Alstonia constricta

If you’re quick, you’ll be able to catch this tree while it’s still in flower at Peacehaven Botanic Park, Highfields. The flowers have a very unusual musty sweet smell.

This is an unusually large specimen, retained from what must once have been a significant area of semi-evergreen vine thicket (dry rainforest) on the Peacehaven site. Nowadays, we usually see bitterbarks as slender little trees or shrubs, able to be picked out from a distance by their attractive white trunks. If damaged, they have a tendency to sucker and produce thickets (or hedges).

this is a fast-growing, drought hardy species, with garden potential, but rarely used.

This is one of those rainforest plants - some of them only found in dry rainforest ecosystems like those which once covered much of our local land - which may suddenly find itself highly valued in the future because of its potential to provide the pharmaceutical industry with a new drug.
Its white latex has been used to lower blood pressure, and some Alstonia species are also showing potential as a source of cancer cures.

Our early settlers would add the bark as a “bitter” to their medicinal concoctions and drinks, but I don’t recommend it! (There’s too fine a line between medicines and poisons.)
However, you might like to experiment with the bark for dye-making. A related species is used for this purpose in India. (Expect yellow.)