Thursday, November 27, 2008

Austral Cornflower

Leuzea australis  (Rhaponticum australe, Stemmacantha australe)
Family: ASTERACEAE
I was astonished to hear that this rare and threatened plant had been found growing on a neglected block in Toowoomba a few years ago. It must have been the last city refuge for this plant, though it would once have been common here. It used to be found on our local red ridges and blacksoils, wherever those very common local trees, mountain coolibah (Eucalyptus orgadophylla) and narrow-leafed ironbarks (E. crebra), are found. In town, gardeners usually mistake it for some kind of milk thistle, and weed it out. In the country, the livestock have done the job instead. So plants growing wild are now very rare indeed.








It is one of those native plants which you’d have to classify as “almost ornamental”. Planted in quantity their spring flowers do make a rather attractive garden statement, with their globe-artichoke-like heads.










Their light brown seedheads have an almost animal appeal. I find myself wanting to pat them on the head like little lambs.
In fine weather, the seedheads are long-lasting. However,  they don’t stand up well to rain and wind, and soon look messy in poor weather. A firm hand with the secateurs is needed to keep the garden looking pretty.


A few heads should always be saved for seed, of course, and they’re easy to reproduce this way.







For those who have enough land to be able to afford some “rough”, this is a good plant to naturalise there, as it provides food for little birds and herbivores.

17 comments:

Sally said...

these are quite weedy in my garden

Patricia Gardner said...

I'm not sure whether to commiserate or congratulate, Sally. They are rare and endangered, having been almost exterminated by grazing animals, so it's good to hear they're re-establishing well on your blacksoil site. (They self-seed, but are not weedy, on my red.)
And they do look their best in groups.
But it's no fun to find you've planted a weed, of course.
You tell me they're very susceptible to glyphosate, so I trust they'll not be an actual nuisance to you.
Trish

darrklogik said...

Hi there,

Thanks for sharing this wonderful news. I also live in Toowoomba, and have been desparately trying to get a live sample of this rare species. I would be willing to compensate you for the trouble Sally. Unfortunately they are classed as weeds by the Australian Government, but I believe their actual origin is Russian.

Regards,
Omar

Patricia Gardner said...

Hi Omar
I’m surprised at your remark that our government classes them as weeds. They are listed as vulnerable by the Commonwealth Government under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC), and by the Queensland Government under the Nature Conservation Act 1992. They are listed as presumed extinct under the Threatened Species Conservation Act 1995 (NSW). All this government attention doesn’t suggest that they think it is a weed!
Trish

Grey_Gum said...

Hi Trish,
I think Omar may be confusing our native species with the Russian and European species Rhaponticum carthamoides.
I personally think the status of Rhaponticum australe should be upgraded to endangered. It has become extinct in Victoria and New South Wales and many people have noticed a serious decline in both the size and number of sites on the Darling Downs. I know of at least 10 sites that have gone the way of the dodo in the last 10 years. In fact some of those sites were lost in the past 3 years. Also I do not know of any national parks or reserves where this species can still be found with certainty, except perhaps for McEwan State Forest, which is tiny really.

Regards
Ian

Grey_Gum said...

I also meant to add in my previous post that many rare species can go berserk in garden culture, simply because they are given a free run, which they seldom if ever get in the wild. It would be a shame if we should allow our perceptions of plant behaviour in the garden to limit our understanding of this species and its rarity. The way plants behave in the garden is not always a reflection of their ecology in the wild state.

Patricia Gardner said...

Thanks Ian.
I was unaware of Rhaponticum carthamoides, having never looked beyond our own natice species. There also appears to be another weedy Rhaponticum in this district, Rhaponticum repens which I think comes from Russia as well.
It's good to have Omar's query explained.
Trish

MC said...

Hi All,
Thankyou for interesting post. I have been following this on and off for the past 6 months always finding new things on here.

I think we have suitable habitat for this species in the area so I am hoping no herbicide use and a good eye for detail we may see it. We definitely have plenty of Onopordum sp. Although with the density of exotic grasses here I am not sure we will find much. Although did have Smabucus gaudichaudiana pop up recently.

A bit of background: I am a supervisor working on riparian restoration of the Burnett river near Gayndah. We are currently working on an organic orchard which has mix of both riparian and not so riparian habitats that are being restored.

Patricia Gardner said...

Hello MC. Thank you for your post.
It would be wonderful if you can find Rhaponticum on your site. If not, you might consider trying to re-establish it as part of the restoration project. (Plants sell at Crows Nest Community Nursery - but would need to be picked up, as they do not deliver.)
How satisfying, to find Sambucus gaudichaudiana popping up on your project. It's a satisfying feeling, when one finds one has created a suitable situation for the native plants to begin to return in the natural way.
All the best with the project.
Trish

Rosalie said...

Hello Trish. I am going to make this plant the subject of my 100 day art challenge starting today. I really like this plant. It pops up in my garden amongst yellow buttons and native mint in my little garden meadow. It has wonderful textures for art.

Patricia Gardner said...

Hi Rosalie.
What an excellent project for keeping busy in this time of enforced isolation. I hope you will show me some of the results.
Trish

Brett Robinson said...

Hi all. Concerning the spread of this plant; it does very well in my garden on good Toowoomba red clay loam. I assume that the original plants from the Crows Nest nursery weren't the exotic weeds, but in just one year they bred from 2 to 200+, including finding tiny gaps in the kikuyu lawn. It completely avoided the shade of my rainforest, and only spread about 20 metres, probably because of the large, heavy seed. Any broadleaf herbicide knocks them dead in the lawn. Strangely, the last couple of years the weather or birds or something has been unkind to them and there were just a few plants and seedheads. Feast or famine with this one, it seems.

Patricia Gardner said...

Hello Brett.
Your plants from the Crows Nest Nursery are definitely the genuine article, Brett - an endangered plant of local origin. As you can see from Sally's earlier comment they can come up in droves, given the right environment and luck with rainfall at exactly the right time.
It is not usual, though, and you will probably find that your plants settle down to a more reasonable reproduction, with the natural variation of conditions as happens with our climate.
Meanwhile, if the extras annoy you you can weed them out or mow them off. You could also leave a generous number in place, for your own enjoyment, and the benefit of the wildlife (especially butterflies) which appreciate them.
I looked more closely into the comments about weedy species of Rhaponticum in Australia. (They are also called Stemmacantha, or Leuzea - Stemmacantha carthamoides, Leuzea repens etc.) I can find no record of them as naturalised plants growing in the wild in Australia. They are banned in several states (and should be banned in them all. There are warnings in all states that any of these species have potential to become environmental weeds, and should not be imported into Australia because of their potential to damage Australia's ecology.
They are, however, commercially available in this country from several irresponsible internet sites.
Cheers
Trish

Anonymous said...

Hello, would anyone have seeds available?
Regards
Crystal

Patricia Gardner said...

Hi Crystal.
You have not said in your comment where you are. This is a Toowoomba blogsite, but of course our readers come from all over the world.
If you are a Toowoomba person, maybe you could drop me a line by email. The address is on the site - just needs a little searching for the big screen view if you are using a phone to access the blog.
Trish

Grey_Gum said...

Just a few fact checks.

1) Unlike our native Rhaponticum, R. (Leuzea) carthamoides is extremely difficult to grow. It is o the Red list for a reason. It needs a lot of cold and if soil and conditions are not exactly to its liking it will fail to grow. People have tried it in the past for commercial purposes by Government in various states. In all cases they failed. It seems to succeed quite well in some colder regions of Canada, and in Europe. It was banned as so many exotic species are, holus bolus according to the suspected habit and repute of some individuals within the genus. Essentially it is the age old precautionary approach to quarantine.

2) Rhaponticum australe becomes weedy in cultivation due to a lack of competition. However, given time it tends to decline in garden situations, unless given attention, and in many cases dies out in most gardens. We cannot rely on garden culture to save this species from going extinct in the wild.

3) Fast forward to 2023, and this plant is in serious trouble on the Darling Downs. Today all of the old sites I knew of around Toowoomba are either slashed bare, have houses on them, or are overgrown with exotic grasses and weeds. Climate change is driving the spread of exotic pasture grasses like never before. The rapidity of negative environmental change is truly mind blowing. I would not be surprised if R. australe goes extinct in the wild on the Darling Downs within the next 10 years or so.

Patricia Gardner said...

Thank you for the comments.
I completely agree with your concern about the risk of the plant becoming extinct. We badly need more nature reserves, and VERY badly need to encourage our local and State Governments to put more money into personnel whose job it is to keep exotic weed infestation down. Relying on just a few reserves maintained by elderly volunteers, rewarding them with certificates and a once-a-year morning tea, is not good enough.
I would have to say, though, that there seems to be a discrepancy between "becoming weedy in cultivation" and "tends to decline in gardens".
In my garden (red soil, close to the Range) I find that it appreciates a bit of help with spreading the seeds about and scratching them into the soil. I think I would eventually lose it otherwise. However it is encouraging to see landholders, on the black soil which is its true natural habitat, re-introducing it to their land using plants bouthe at Crows Nest Community nursery.
Keep up the good work!
Trish