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I've been a Canberran since moving here from Adelaide on the first day of 1980. I now live in suburban Duffy with my partner Louise Maher, ABC 666 radio and on-line journalist. Among my early memories is following Sleepy Lizards (Shinglebacks) around the paddocks north of Adelaide, guarded by the faithful bull terrier. I have always been passionate about the natural world, trying to understand how it works, how the nature of Australia came to be, and sharing those understandings. My especial passions are birds, orchids and mammals. For much of my life I have been a full-time naturalist, running bush tours, writing books etc, doing consultancies, presenting a regular radio slot on local ABC, chairing a government environment advisory committee and running adult education classes. Recently I have eased back somewhat, but am still writing, teaching, doing some radio work and running overseas tours - as part of my fascination with our Gondwanan origins I've been running tours to South America for the past decade. I was awarded the Australian Plants Society Award in 2001 and the Australian Natural History Medallion in 2006, both for services to education and conservation.

Thursday, 22 January 2015

Kurrajongs and Bottle Trees

With a title like that you might reasonably suspect a joke on my part, but in fact this is the latest in my sporadic series on favourite trees; you can find the most recent instalment here and find earlier ones from there if you so wish.

I grew up with some of the Australian children's classics, including May Gibbs' Snugglepot and Cuddlepie series, very whimsical (and somewhat downright scary) and very Australian, with the characters based on bush flowers and fruits. I'll leave you to investigate further if it's new to you, but one thing that always intrigued me was their use of Kurrajong pods as boats. In Adelaide we didn't know Kurrajongs, but when I moved to eastern Australia I was delighted to get to know them, and the members of the genus Brachychiton are now among my favourite trees. Around Canberra and onto the western slopes Kurrajong B. populneus grows in a range of drier situations from rocky hillsides to deep plains soils. (The myth that Kurrajong indicates the presence of limestone appears to be just that.)
Kurrajong near Molong, New South Wales.
A lovely spreading tree with soft glossy green foliage that shines in the breeze.
The seed pods, the May Gibbs boats of my childhood reading, contain stinging hairs,
but the seeds if winnowed can be roasted and used in a beverage.
The genus name Brachychiton translates as a short Ancient Greek tunic, in somewhat whimsical reference to the loose covering of the seed. Populneus is a reference to the supposedly poplar-like nature of the foliage.
Kurrajong leaves; the three lobed form is often a character of younger trees. These leaves are quite soft,
unexpectedly so for an Australian dry country plant.
The foliage is a reason that Kurrajongs are often left in otherwise largely treeless rural landscapes; the leaves are valuable drought fodder and branches are cut in hard times to feed sheep and cattle. The tree recovers. 
The palatability of the leaves can be readily deduced when a Kurrajong grows on a fence line.
Outside the fence (on the left) the foliage sweeps down to the ground; inside stock have
browsed it as high up as they can reach.
The origin of the word Kurrajong itself is somewhat confused. It seems that it is probably one of the few words remaining of the language of the people who lived where Sydney now stands; their name or language might have been Dharug, as is often asserted, but not all experts are convinced. However the word seems to have referred to a fibre used for lines or fishing nets, and deriving from a native Hibiscus (H. heterophyllus). Somehow the word got to be used for 'our' Kurrajong, which grew on the Cumberland Plain to the west of Sydney. It has also been applied at times to species of Pimeleas which, like the Kurrajong, were also valued for their fibrous bark. Too often we didn't pay enough attention to what we were being told and I've wondered if many of our forebears merely confused the word for the fibre with the various plants it derived from.

However the Kurrajong is just one of 31 Brachychiton species, all of which are Australian but for one New Guinea species. Until 2006 they were broadly accepted as being in the family Sterculiaceae, but then a detailed genetic study determined that Sterculiaceae was really an artificial family, and most of its members (along with those of other related families) were moved into the hibiscus family, Malvaceae. That seems to have since been generally accepted.

The flowers are distinctive - and not very reminiscent of hibiscus, it must be noted. They comprise a tube of fused sepals (not petals, it seems, despite their colouration). 

Kurrajong flowers, Pilliga National Park, New South Wales.
Others are more brightly coloured.
Red-flowered Kurrajong B. paradoxus, Litchfield National Park near Darwin.
A small tree of the tropics.
Flowers of Illawarra Flame Tree B. acerifolius carpeting the forest floor, Chichester State Forest, New South Wales.
Like other forest species, this one is deciduous, flowering after the leaves have dropped,
producing a spectacular effect.
At the other habitat extreme from the wet forest Flame Tree, there is a Brachychiton native to the harsh central deserts too.
Desert Kurrajong B. gregorii, Mereenie Loop, central Australia.
The species name is for Augustus Gregory, the explorer who collected the type
specimen far to the west on the Murchison River in 1848.
Desert Kurrajong fruit - the close relation with Kurrajong is obvious.
Perhaps the most widely recognised member of the genus however is endemic to inland south-eastern Queensland. The Queensland Bottle Tree is instantly recognisable by its oddly bulbous trunk at its mid-height, which intrigued the explorer Thomas Mitchell when he encountered it near where Roma now stands in 1848 (coincidentally the same year that Gregory discovered the Desert Kurrajong on the far side of the country). He considered, understandably, that it "looked very odd".
Queensland Bottle Tree B. rupestris near Tambo.
However, Kath has kindly commented below that she thinks this could be Broad-leaved Bottle Tree, B. australis,
which isn't as massive as B. rupestris. I'm not in a position to disagree (see my comments
below hers) and she could well be right.
The landscape dotted with these magnificent trees makes the drive through central Queensland worth it just for that. (And incidentally they are not at all the same as the Baobabs of north-western Australia, Madagascar and Africa, though the recent taxonomic revision has put them into the same family.) They dominate now scarce and threatened vine scrub habitats.
Queensland Bottle Tree (this one I am sure of) dominating vine scrub at
Lake Nuga Nuga NP, Queensland.
Several species, especially tropical ones, are deciduous in the dry season.
Broad-leaved Bottle Trees B. australis, leafless in winter, Undara NP, north Queensland.

My love affair with kurrajongs and bottle trees is not wholly platonic - our relatively small front and back yards host a Kurrajong and Queensland Bottle Tree respectively, and they're showing every sign of returning our affection by thriving.

I hope you can share my enthusiasm for them.

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8 comments:

Flabmeister said...

One of my memories of Adelaide is that there was little need for a boat, whether made from Kurrajong seeds or not, as the rivers in that vicinity were, as Mark Twain said of the South Platte. "Too thick to drink, too thin to plough".

Possibly a more helpful comment is to refer to the collection of 178 Kurrajongs on the road leading from Inverell to Glen Innes. These have been planted as a War Memorial, reflecting Kurrajong as the nickname of the regiment recruited in that area. There is one tree for each member of the regiment who was killed in WW1: that must have been a large proportion of the men in the area.

Martin

Susan said...

I'm a big fan of kurrajongs and their relatives too. They make great garden trees and I love to encounter them in the wild.

Susan said...

Oh, PS, I also love the Snugglepot and Cuddlepie stories. We had them in a big book as kids. Some of the characters are really scary for kids. The illustrations are wonderful.

The happy wanderer. said...

It's interesting what changes in classifications DNA has had in the natural world. We saw several different baobab species in Madagascar recently, but can't remember the details!

Kath H said...

I wondered whether the last picture of a Queensland bottle tree was actually Brachychiton rupestris. It looked a bit more like a Brachychiton australis? It looks a bit tall and not bulging enough to be a B. rupestris.

Ian Fraser said...

Thanks all for your comments; due to the magic of Blogger I was actually in Darwin when that post went up, so am only now able to respond.

Martin, your comment on the New England kurrajong memorial planting reminds me peripherally of something else I could have mentioned. Recently in Santiago I was surprised to see an impressive collection of Brachychitons planted along the edge of the Plaza de Armas in the centre of town.

Thanks Susan - you sound a bit nostalgic!

Ah HW, Madagascar - that's a destination for a natural historian to sigh over!

Kath, thanks so much for that observation. I'm not very familiar with B. australis and had assumed it was tropical in distribution but I now see that's only part of the story. So you're very probably right, and I've just learnt something I'm glad I know - again my thanks, and I'll amend the photo caption accordingly.

Flabmeister said...

I recently visited Wee Jasper, and was astonished to see the Kurrajongs growing out on tiny cracks in the limestone outcrops around Carey's Caves. While it may be a myth that the species indicates Limestone, based on this sample of 1 site, the trees certainly like the rock!

Martin

Ian Fraser said...

Agreed Martin - but they also like other sedimentaries, granite and deep soil.