Spring: wattles of the Australian Capital Territory

Wattle Day (on 1 September, the first day of our spring) was a week or so back as I write this, but it's only really started to feel 'springy' here in the past few days. As you probably know, Australia uses the Meteorological definition of seasons - that is they start on the first day of the month which contains the equinox or solstice, whereas in much of the rest of the western world at least they use Astronomical seasons, which start on the actual equinox/solstice. I read recently that in Finland and Sweden spring begins when the mean temperature over five consecutive 24-hour periods rises above 0 degrees centigrade; this does mean that spring starts on different days at different latitudes within the country. (For the record a mean 5-day average of above 10 degrees means summer, and of below 0 means winter. I quite like the concept, though I'm uncertain what happens if spring is declared then the mean drops below zero again...)

Spring in Canberra; massed Box-leaved Wattle Acacia (hereafter just A.) buxifolia, in September.

All this confirms of course that it is simple human conceit to rigidly define seasons; I'm on record as saying that spring in Canberra really starts when the little blue orchid Cyanicula caerulea first flowers, but that means that spring's official welcome varies from year to year. I'm OK with that, but I don't expect widespread acceptance any time soon. (However in northern Australia the traditional people of Arnhem Land define their six seasons by just such a system, so I'm neither alone nor original.)

For many of us the first wattle flowers of August are harbingers of better days to come (though in truth there's a wattle flowering somewhere on any given day of the year, and at least one local special flowers in winter). Some time ago I was asked to do a posting on local wattles, and finally here it is! It's a simple photo essay, introducing most of our native species (just over two thirds of them anyway, 16 of 23) in alphabetical order, lest I be accused of favouritism, and ending with a couple of non-locals which are widely established. Most of the absent seven here are scarce and/or grow in relatively remote areas of the ACT. I think I'll only need to use one photo taken outside the ACT.

Here we go then!

Box-leaved Wattle again, also on Black Mountain, above and below.
Locally it is found mostly on stony soils in the north of the ACT.

Box-leaved Wattle close-up; the little phyllodes are generally only 15-20mm long.
The common and scientific names both refer to the supposed resemblance of the phyllodes to the mostly
Northern Hemisphere boxes, Buxus spp., and probably in particular the common European B. sempervirens.

Poverty Wattle A. dawsonii, Molonglo Gorge.
Found mostly on low-nutrient rocky soils in dry areas above waterways in the north of the territory.
Seemingly named for otherwise little-known 19th century NSW surveyor and plant collector James Dawson.

Massed Silver Wattle A. dealbata, Namadgi National Park.
One of the most widespread and conspicuous local wattles, forming dense understoreys in both
dry and wet forests. In higher rainfall areas in Victoria and Tasmania it can be an impressive tree
to 30 metres tall; it has been used for furniture timber.

Silver Wattle detail; dealbata means 'whitewashed'.
It is probably sometimes mistaken for the locally exotic Cootamundra Wattle (see near end
of posting for distinctions), and probably vice versa too.

Spearwood Wattle A. doratoxylon (the common name is the translation of the scientific one, for a reported
Indigenous usage). In this picture the wattle is the somewhat wispy one in the foreground, below the
Black Cypress Pines in Molonglo Gorge. The species is widespread on rocky ranges to the west of here,
but in the ACT is restricted to this rocky gorge.

 

Broad-leaved Hickory Wattle A. falciformis, Namadgi National Park.
Found commonly at mid-altitudes across the ranges of central ACT, a handsome small tree.
The name means 'sickle-shaped'.

Early Wattle A. genistifolia, Black Mountain, above and below.
A prickly shrub, but delightful, especially as its pale flowers shine through the winter months.

The name means 'broom-leaved'.

Ploughshare Wattle A. gunnii, Black Mountain.
Named for the triangular phyllodes (which have very efficient little spiked tips), and for Ronald Gunn,
Tasmanian 19th century naturalist and collector for whom many species are named.
This one is found from South Australia to Tasmania to south-east Queensland.

Hickory Wattle A. implexa, Black Mountain. Sorry about the absence of flowers, which come in summer.
This small handsome tree grows in dry forests in the north of the territory.

Black (or Green!) Wattle A. mearnsii, Narrabundah Hill; this is one of the commonest and most
familiar wattles around Canberra, but not so much to the south of here. Its flowering is dramatic.

Black Wattle, Jerrabomberra Wetlands.
The name is bizarre; the very short version of the story is that in 1925 a US collector named Edgar Mearns collected
some specimens of it growing near Nairobi, where they had been planted, though neither he nor the Belgian
botanist De Wildeman to whom he gave the specimens realised that. (Why they thought that a new Acacia,
and not of the African type at all, should have been unnoticed there is beyond me.) De Wildemans, unaware that
the species had been described well over 100 years previously, treated it as a new species, and called it A mearnsii
after the collector. For obvious reasons the name was immediately ignored - until some detective work by
Kew Gardens researchers in 1967, who discovered that the original early 19th century name was invalid
(due to a crazy confusion of mismatched description and illustration), and mearnsii was the
next available name! There's not much more justice in taxonomy than there is in life sometimes.

Blackwood A. melanoxylon, National Botanic Gardens - and I can't believe that I don't have a 'wild'
photo of this wonderful tree, which is quite common in the ranges. It grows from the Adelaide Hills to
tropical Queensland, but in Tasmania and Gippsland in particular it grows into a huge tree, much sought after in
times past for furniture and panelling. Indeed the wall panelling and the doors and frames, including the massive
external front door, of Australia's original Parliament House, are made of Blackwood.
Melanoxylon (properly pronounced mel-an-oh-ZIE-lon) just means 'black wood'.

The lovely, almost white, flowers of Blackwood, high in Namadgi NP.

Blackwood pods, Namadgi NP.
The red arils are nutritious, and serve to attract ants to carry the hard (inaccessibly so) fallen seeds to the nest,
where the seeds are discarded, well away from the parent tree, and the arils taken in as food.

Mountain Hickory Wattle A. obliquinervia is found in mountain forests right up to the Snow Gums.
This one is regenerating in Namadgi National Park in the aftermath of the massive and intense wildfires of 2003.

Mountain Hickory Wattle, Namadgi National Park. If you click on the picture to enlarge it,
you will see that the mid-vein of each phyllode is off-centre - obliquinervia of course means
'oblique-nerved', referring to the veins.

Kangaroo Thorn A. paradoxa, Mount Ainslie, above and below.
This spiky tangled shrub was widely believed, for reasons uncertain, to be exotic in the ACT,
but that seems not to be the accepted view now. I don't know the significance of the 'paradox' in the name.

The pair of stem spikes beneath each phyllode are evident here.

Wedge-leaved (or Oven's) Wattle A. pravissima, Namdadgi NP, above and below,
is widespread in the lower slopes of the ranges, flowering profusely in early spring.
It is also widely planted. The species name means 'very crooked' for the stems.

The diagnostic triangular phyllodes are the best identifier.

Golden Wattle A. pycnantha,  Lincoln NP, South Australia. This is Australia's national
floral emblem and widespread in south-eastern Australian, but scarce in the ACT.
Mount Ainslie is probably your best chance of seeing it here.

Redstem Wattle A. rubida, Namadgi NP (all three pictures). A widespread and common
species, around Canberra and well up into the ranges.

These curved phyllodes are not universal in the species.

This photos shows both the red stem of the names, and an interesting characteristic,
wherein both juvenile foliage (pinnate feathery leaves) and adult phyllodes (flattened leaf stems)
occur on the same plant. To the right you can see the pinnate leaves growing from an already flattening stalk.

Dagger Wattle A. siculiformis, Namadgi NP, above and below.
Common enough along creek lines and swamp margins of the ranges.

The wickedly tipped phyllodes and the flower heads at their base are both characteristic.

Finally, a couple of  widespread wattles in the northern ACT which are (probably) not native to here, mostly originating from plantings.

Green (or Black!) Wattle A. decurrens, Cooleman Ridge - see also A. mearnsii, which it closely resembles.
It is generally agreed that it was not originally here, though it grows nearby. It flowers in early spring (A. mearnsiiblooms later) and has distinctively ridged branchlets.

Cootamundra Wattle A. baileyana, Black Mountain, above and below. A very well-known plant which grows
ferally across much of south-eastern Australia, but has a very limited natural range to the south-west of here,
with little of that included in reserves.

It could be mistaken for Silver Wattle, but Cootamundra Wattle has only three or four pinnae (leaflet-bearing
stems) per leaf-branch, compared with up to 20 for Silver Wattle.

So there it is, our local wattles (or most of them). Enjoy them, and spring - however you define it - and we can all only hope for some rain soon...

NEXT POSTING THURSDAY 27 SEPTEMBER (by when I'll be in Brazil)

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