This forum tends to focus on temperate plants in North America, so you're unlikely to get a helpful response.
Try googling "Australia Gardening Forum".

I see posts from other countries on here all the time, and I have no problem trying to help someone from other countries find a plant, BUT this is a little harder than some of the other plants I've looked for. Use the correct scientific name, Cassia javanica, for best search results. Here are a couple of non-Australian sources that have this plant in stock. These two sources came from a private database. I don't know what their policy is about shipping overseas or non-wholesale orders, but if you are serious about the search, you can check them out.

TreeWorld Wholesale
24605 SW 192 Ave
Homestead, FL 33031
305-968-2427
786-877-5167

Aloha Tropicals
P.O. Box 6042
Oceanside, CA 92054
760-631-2880
alohatrop@aol.com

Here is another possibility, but I don't have access to their inventory to see if they actually have it currently.

Pacific Trees Qld
PO Box 3820
Burleigh Town Qld 4220
07-5596-5801
bruce@pacifictrees.com.au

I actually found that last source with a Google query of ' "Cassia javanica" nursery '. (Sorry I can't link to the seach. Of all things, Google seems to be the hardest to link to these days.) There are lots of other search results, but the first couple seemed to show out of stock. Hope this helped a little.

"I see posts from other countries on here all the time"
I do too, but as you admit we're not really in a position to help someone in Perth find this plant.

I found plenty of promising links with "Cassia javanica western australia" in google - so maybe this is also a googling help forum! All things considered, for a remote country with only 22 million Australia has a quite vibrant gardening culture. Having to ask on a yank forum for a source is a variation on a "coals to Newcastle" theme, I daresay.

This nursery is in "the WA" and might prove helpful:

Here is a link that might be useful: http://ellenbytreefarm.com/products/cassia-fistula-golden-shower-tree

This post was edited by davidrt28 on Fri, Mar 28, 14 at 17:05

"...as you admit we're not really in a position to help someone in Perth find this plant."

I didn't have much luck with this particular plant, but very well might with many others. I (and a few others that frequent this forum) have a number of resources that many people don't have easy access to. Some of these could indeed help me find Australian sources for plants.

On top of that, there are GardenWeb members that actually live in Australia that are in this forum occasionally. I don't know what resources they might have, but it never hurts to ask.

" have a number of resources that many people don't have easy access to"

Which resources, pray tell? Academic databases? I suppose scholarly articles might sometimes discuss plant sources; but the few times I've seen this it's almost invariably a wholesaler.

Anyhow our first time OP is probably long gone by now...hope he/she finds their Cassia!

David, we might want to take further conversation of databases to another (more related) thread. But many larger nurseries (both retail and wholesale) provide access to the inventory via a password-protected access. There are also professional organizations, including international ones, that provide search access via composite databases. Many of these require proof of industry association for access. I'm not familiar with "academic databases" related to this, at least that I can think of right now.

For the non-professional there are somewhat similar databases like Dave's PlantScout. It can be fairly useful for some things, but is not nearly as broad reaching as industry tools. I still consult it in addition to other resources. For retail mail-order, PlantScout's links to Garden Watchdog can be a plus.

Oreliaman, I noticed that you are new to GardenWeb. Please don't let the discussion above discourage you from posting further. I think most people here enjoy answering questions and helping people find stuff, as long as they've done some homework. The plant you were looking for is apparently not all that commonly available, so asking here was fine, IMO. If you are still around and find your plant, please let us know!

Brandon, sorry for being a bore. Don't take my tone the wrong way. I enjoy your contributions.

Orelianman, I hope I didn't scare you off and I shouldn't have phrased my first response in a gentler way. I didn't want YOU wasting your time...I happily waste my time at gardenweb! There just aren't many Australian posters here who seem like serious gardeners, so I assumed they all post on some Australian gardening forum that ends in .au somewhere.

Brandon, OK, thanks I see what you are talking about now; by "Academic Databases" I meant the databases accessible to people in US academia, like OCLC, that catalog all of the world's academic research. With articles that publishers would otherwise try to ridiculously charge $39.99 for. Though it doesn't surprise me that there is some kind of "industry only" plant finding services, IMHO the most serious has always been available to the public in one form or another: the UMN plantfinder. It was available as a book since at least the early 90s IIRC, and there's been a web version for years. It's very useful for mail order nurseries but they also cover wholesale only sources. If you are aware of a superior offering from a commercial provider who expects to get paid for it, do let me know, I'd be curious to know about it. As for wholesale nurseries more and more of them seem to at least have the sense to put their availability lists online w/o prices. Don't get me started on the antiquated way high end plant material is sold in the country. Monrovia might be what Talon Buchholz calls one of the "evil nurseries" but selling direct wholesale-to-consumer is the wave of the future. If I can order a single resistor from mouser when they probably have over a million SKUs and many customers with multi-million dollar accounts, it's ridiculous I can't do the same from wholesale nurseries.

Here is a link that might be useful: http://plantinfo.umn.edu/

This post was edited by davidrt28 on Sat, Mar 29, 14 at 18:47

Or for that matter, a single screw from McMaster-Carr. World's most beautiful website of commerce, Edward Tufte must have heart palpitations when he browses it.