altum versus kosaninii

Dear all,

This is not a question about some lost-label plant, but it is about identification, so I think that it best fits here.

I have S. altum from Mont Armichi and S. kosaninii from Ohrid. I obtained both plants from Erwin Geiger, so I assume that the identification is correct. Their localities of origin are far away from each other, but to me they look extremely similar. Maybe this will change when they grow, they are both small rosettes at the moment. But these two look more similar than what I know of 2 clones from tectorum growing right next to each other in nature.

I wonder, can someone tell me which characters I should look at to distinguish the species S. altum and S. kosaninii (regardless of which clone it happens to be)? Why are these described as different species apart from the large distance between them?

Paul

I can't help you much, but I think that S.altum should have much longer stolons.
Many species look similar at some stage but they differ in other stages and in some parts that are not always visible (like stolons or flowers).