Sophora secundifora 'Silver Peso'

There is a wonderful drought tolerant tree that has beem called for in our new landscape called Sophora secundifora 'Silver Peso.' Unfortunately, it is very difficult to locate here in California, being more common to Arizona and Texas.

Does anyone know where to find it? This cultivar has blue-gray leaves and purple wisteria like blossoms that smell like grape bubble gum. Very striking! And perfect for a small space.

Thanks.

I finally found it after contacting a wholesale nursery in Tucson who by pure luck was delivering a few to Walter Anderson's nursery in Poway. I think they only got a few and were keeping some for propagation. Nancita