Tuesday, 4 September 2007

Chillagoe kurrajong

I made a list of things I wanted to see in Chillagoe. It was a modest inventory: bustards, snails and the Chillagoe kurrajong, Brachychiton chillagoensis. I ticked them all.

Brachychiton is a principally Australian genus, with a few species in Papua New Guinea. It occurs in seasonally dry habitats in eastern, northern and central Western Australia. Most species drop their maple-like leaves when water is scarce, although a few, like B. populneus and B. gregorii hang onto them until severe drought forces them to cast the leaves off.

This kurrajong is endemic to the Chillagoe – Almaden area, where it grows on the fractured, crumbling slopes of rock outcrops. It also occurs in the dry vine thickets that nestle between limestone cliffs, where they're sheltered — a little — from fires. I have a soft spot for kurrajongs, although I know next to nothing about them, so I wasn't going to miss the chance of visiting this one in its home. I'm also fond of short-range endemics — and I know rather more about those — so I was doubly excited by the opportunity.

The tree is recorded as flowering from late May to October, but only a few bell-shaped blossoms clung to the branches of the individuals I saw.

'You're not going to take a photo of that?' one of my friends asked as I scratched away debris to uncover a fallen flower.

'Why, yes. Yes, I am.'

And I got the sort of look that I might have received had I been on the wrong side of the bars at Bedlam.

But I took the photo anyway.

As kurrajongs shed their leaves when they bloom, a tree covered in these blossoms must be a spectacular sight. And I missed it by that much. Next time ...

Fallen flower at Balancing Rock, Chillagoe – Mungana National Park

The last few buds at the side of the road

The leaves have characteristically rounded lobes

New seed pods on a roadside tree

Deeply fissured and tessellated bark

It occurs with another species, the broad-leafed bottle tree (B. australis), which has a much wider range. (This more common species extends from west of Cooktown south to Wide Bay.) The two are readily distinguished on the shape of the leaves and the different bark textures. And no doubt on the flowers too — at the right time of year. Which, I shall note in my diary, is not late July, no matter what the definitive work claims.

Brachychiton australis doing it tough on a limestone outcrop

Really tough ...

The bark is paler and relatively smooth compared with that of B. chillagoensis

The leaves are also more pointed and deeply dissected

Reference
Guymer, GP. (1988). A taxonomic revision of Brachychiton (Sterculiaceae). Australian Systematic Botany 1: 199 – 323.

2 comments:

Kevin Z said...

I was surprised to learn the Brachychiton was not a mollusc, much less in the animal kingdom!

Happy travels!

Snail said...

We can make it an honorary mollusc!