try here:

Here is a link that might be useful: Arizona Living Landscape

Thanks for your reply. Turns out that the shrub that I am looking for is probably not a knife leaf acacia, or is a different shrub with the same common name.
I saw this shrub at Leaf and Feather, in Maricopa. they did not know the name but thought it was a knife leaf acacia. It is a shrub that handles AZ weather, and loves some shade. The stem is flattened like a knife, looks leaf like, and with one leaf growing out the other. The stem as small thorns. Looks like two per 'leaf'.
I believe it is an Australian plant, and the owner said he has never seen one elsewhere other than a Lowes at one time, and it was outrageously priced, but was a large specimen.
they propagate it from seed, but had no small plants at all. If you are in the area, the shrub is growing right next to the monkey cage. Even after the freeze, this plant was still green with no damage. I searched almost every nursery here for it, with no luck
this is a must have plant for me. I am leaving AZ in two days, but will be back in a few months and will look again, if no one else can find it for me.
thanks