Australian Orchid Foundation
 

This vendor is a supplier of seed and protocorms of many highly desirable and hard to find in the US species of Australian terrestrial orchids, such as Thelymitra, Caladenia, Diuris, etc. I actually tried to order over a year before I got these, and never heard back. They had some issues a while back with questions over the legality of what and where they could ship, but those issues were worked out and they can legally ship seed to the US. My package was clearly labeled as to contents and went right to customs upon entry. It cleared and several days later I got my seed. Germination via the cardboard method has been very good with the 3 Thelymitra species, however none with the Diuris. It could be they're not amenable to the method. In any case this is a reputable way to get Australian terrestrial in the US, which is a really good thing!
Seed and Protocorm Bank The Australian Orchid Foundation