Annette,
Tissue cultured plants appear to have a different root structure (at least to my eye) in which the eyes form a very tight clump on the crown (pictured here -
http://garden.org/thread/view_...). As I remember it, the crown is also somewhat spiral shaped. Sorry for the poor description; it makes sense in my head. Many of the garden centres around these parts carry Itohs provided by a supplier who propagates by tissue culture. As I made the transition from a casual gardener to someone who is a little more educated on peony culture, I learned along the way that I have acquired quite a few tissue cultured plants. So far they seem on track, but it's just coming up on three years for these plants, so I cannot say that with certainty!
