These are some seedlings from fruits of "Sacaton" citrumelo that I picked at Eisenhut's.
I think they look rather odd. Some are completely monofoliate, with winged petiole, others are mono-, bi-, and trifoliate.
In fact, there is only one seedling that looks like a normal citrumelo to me:
There is a large Yuzu nearby. Could these be Citrumelo x Yuzu? Or is it too early to tell?
Thanks!