Wow nice, are they grown in the states yet?

That would be nice to have!! I love small species.

As far as I know, people have never tried these in cultivation. This is the first time live plants are pictured. If they extinct in the wild, they are gone for good. They are so small and fragile. Look at your azalea leaf and think how tiny they are.

There are a number of candidates for smallest rhododendron in the world. How large they grow depends partly on the species, partly on the cultivar, and partly on the habitat and age:

Historically the smallest rhododendron in the world was Rhododendron radicans which looks like the one in this picture. It is grown in gardens including a specimen in Salem, NH.

Rhododendron calostrotum ssp. keleticum which is a synonym for R. radicans.

More recently the title of the smallest rhododendron in the world goes to Rhododendron caespitosum, a tropical vireya rhododendron. There is a specimen in the RBGE (Edinburgh, Scotland) that was recently found in Borneo.

Here is a link that might be useful: Reference in Tales of the Rose Tree

rhodyman,
This is not R. radicans. It is much smaller. It is as small as R. caespitosum. I do not know the species name.

R.telmateium Balf.f.et W.W.Sm

R. telmateium has been grown in cultivation, but not commonly. When grown in cultivation, it is grown under the old names Diacritum Group or Pycnocladum Group. It is a highly variable species found in 1916.