Saturday, January 28, 2012

Herbert’s Passionfruit

Passiflora herbertiana
There are so many weedy introduced passionfruit species in our local bushland, that the locals (two subspecies of P. aurantia, and this one) can easily be overlooked.
However, they both have quite distinctive leaf shapes unlike the leaf shape of any introduced passionfruit, so they are easy to distinguish once you’re in the know.

If in doubt, check out the glands on the stem near the base of the leaf. Their position differs on each passionfruit species. Both our locals have two, which hug the leaf-stem quite close to the leaf (see photo).

Herbert’s passionfruit is easy to overlook because its flowers are not particularly showy - but (with the exception of the introduced passionfruit Passiflora edulis, which has the familiar black fruit and can also be found growing wild) it has the best fruit for eating. They are also our largest local native passionfruits.
As with all passionfruit species including the common garden fruit, Passiflora edulis, the unripe fruits are poisonous. However, the poisons are not so strong that harm would come from a mouthful - and the experience is unlikely to be repeated because of the unpleasantly bitter taste of the fruit. This means that they are unlikely to be a danger to children.
The fruit of Herbert’s passionfruit doesn’t change colour as it ripens. Instead, you can tell whether it is ready for eating by the way it softens. It must be quite soft and squashy for the best flavour. If picked at the right time it is delicious.

The flowerbuds seem to promise colour, with these bright salmon-coloured sepals.

However they open to greenish white, gaining no more than the faintest orange stain as they age.

The plants like to grow in the dappled shade of trees. They are drought hardy, and survive frosts and fires by dying back to their roots, growing again once the danger has passed. This ability would make them amenable to being tidied up with the secateurs once the fruiting season has finished.

Like all native passionfruits this plant plays host to glasswing butterflies (Acraea andromacha.)

Here are some glasswing caterpillars which have made themselves at home on my neighbour’s plant, and are demonstrating how very suitable this passionfruit species is, for wildlife garden planting.

Friday, January 20, 2012

Embelia Vine

Embelia australiana

Plant identification keys often ask us whether the plant that we’re trying to identify has “translucent oil dots”.

This little plant most certainly does!

It’s the dottiest plant I’ve ever seen, as I discovered when I held a leaf up to the light.
(Double click for a good look at those lovely dots.)
This plant is growing in dry rainforest on stony black soil, on the eastern edge of the Great Dividing Range north of Toowoomba. Potentially a tall, slender, woody climber, this is a plant that can grow as a shrub if it finds nothing to climb on.
An attractive plant with its pale-veined leaves, it is characterised by touches of bright red The clusters of pale greenish-brown flowers have bright red calyces The autumn fruits are bright red, and so are the new leaves.
As a garden plant, it would have the added virtue of bringing fruit-eating birds to the garden.

Fern-leafed Germander

Teucrium argutum var. incisum
The native germander familiar to those of us who live in the Toowoomba area is the variety known as “var. argutum”. (See April 2011 for a description of it.)
Less well known is this variety from the dry plains to the west, which has soft, deeply incised leaves. This pretty plant has recently been put in at Peacehaven Botanic Park in Highfields, where the shelter now provided by the maturing trees of the Dry Rainforest section is enabling the planting of smaller plants amongst them to begin.
Its flowers, as you can see, resemble those of “var. argutum” (below) but the leaves are quite distinctive.

Bringing in the Beetles

Melicope micrococca
The white doughwoods are flowering around the district now.
Their flowers are very attractive to insects, and especially to beetles, as you can see from this lovely fiddler beetle, one of dozens which have been coming to my tree.
Plants which attract insects are a good choice for a wildlife-friendly garden, as not only do the insects provide “life” in themselves - but they bring in the birds which prey on them.
See January 2011 for more on this local shade tree.

Thursday, January 12, 2012

Yellow Sunray

Leucochrysum albicans
Sometimes, the names of flowers can be so inappropriate as to raise a smile.
Leucochrysum” is a name cobbled together out of two old Greek words. “Leukos” meaning white (familiar to us from “leukemia”, the disease of white blood cells), and “chrysos” meaning gold.
Albicans” is another reference to whiteness, and just to really rub it in, our local plant is Leocochrysum albicans subsp. albicans var. albicans!

This somewhat overdone insistence on whiteness is all very well for the people of New South Wales, where the petal-like bracts of the plants are actually white - but here in Queensland it is an all-yellow flower.

I photographed these a few weeks ago at the Bunya Mountains, where the plant grows among grasses on dry, open ridges in very well-drained soil.

Yellow sunray is a short-lived perennial, but is often grown as an annual as it will produce early spring flowers from autumn-sown seed, and continues to flower until March. It is a slender plant, with soft, grey-green leaves, and looks best if a number of plants are positioned in a group.

Once you have it in the garden, it would be a simple matter to save seed each year to plant in April.

Narrow-leafed Myrtle

Backhousia angustifolia (Anetholea anisata)
The Backhousia species are all good garden subjects - attractive plants with aromatic leaves, fluffy white flowers (now showing), and bird-attracting fruits to come in autumn.

This narrow-leafed plant of the inland, photographed on a dry, grassy hillside at the Bunya Mountains, is the hardiest of them all, but is less often grown than are its softer cousins.
This is probably because it is not native in the coastal regions near Australia’s biggest cities, rather than because it is any less suitable for gardens.

Shown here as a fairly young plant, it is obviously something that would make a good screen. As it matures, it develops into small tree, which may have a single trunk, or be multi-stemmed - something a gardener can manipulate with judicious use of secateurs. It might reach 7m, but is most likely to be smaller.

The smell of the crushed leaves varies from site to site, with some smelling of curry or lavender. These ones, however, smelled of aniseed.

Thursday, January 5, 2012

Golden Passionflower

Passiflora aurantia var. pubescens

I was mystified when my companions and I found this flower, while walking (on private property) at the Bunya Mountains.

Its leaves looked like those of the familiar red passionflower, Passiflora aurantia var. aurantia, (below), which grows at Picnic point and various other places around Toowoomba, but the flowers were very different.

In the photo above you can see that the petals and sepals of the flowers of the familiar plant, which age from white to red, are always concolorous (a word which means that the back is the same colour as the front.)

Both plants have five rather small petals, and five larger sepals - brightly coloured ones which look like petals.
In our mystery plant, the sepals are discolorous. Their backs backs age from the pale yellow of this bud, to a stronger shade of yellow, always with a hint of green.

The front of the sepals, on the other hand, brightened - as did the little petals - from greenish white...

to deep orange.

The little ring of filaments, the “crown of thorns” in the centre of the flower, was very eye-catching in all stages - a gleaming fluoro orange, quite different from the soft pinkish red of the more familiar variety of Passiflora aurantia.

To our delight, a little research revealed that what we had was indeed P. aurantia - but a rare variety of it. It is P. aurantia var. pubescens, as opposed to the familiar P. aurantia var. aurantia.

The reference book which helped us distinguish between the two(Stanley and Ross. “Flora of South-eastern Queensland”) doesn’t mention the conspicuous differences between the flowers, but focuses instead on the “hairiness” of var. pubescens. (“Pubescent” is a botanical term meaning “hairy”.)

In practice, we needed a good magnifying glass to find the almost-invisible little hairs on the leaves and on the ovary.
(The ovary is that ovoid bit that’s going to turn into the fruit. To see it enlarged, click on the photo.)

Compare these two flowers, and you can indeed see that our golden passionflower's ovary is indeed softly hairy, while the red passionflower's is smooth.

It would be interesting to compare the mature fruits.

Meanwhile, another difference that we noticed was our inability to find any hint of the little glands on the leaf petiole of var. pubescens.
P. aurantia var. aurantia
has a tiny, but easily found pair of them, just near the base of the leaf.
Something had been nibbling the leaves of our golden passionflower vine. Perhaps it was the caterpillars of glasswing butterflies, who may find it is just as good a host as its red-flowering relative. Like that plant, this light vine is something we would love to have in our garden.