Jon Butts and Debbie at EcoFarm grow two types of mystery replicating onions....one the tops die back in late spring, which makes me think it is likely a "Potato Onion" (sub-species of shallot). I just checked the other one out front in a rose bed...they are definitely dividing underground and I THINK they said it grows year round. This is the odd one that Jon says that maybe 1 of every 12 sends up a viviparous stalk, kind of like Allium canadense. The plants are quite petite, DWARFED by my Allium fistulosum and "Eliska's Bunching Onion" which I am about 95% sure is a form of A. fistulosum, both of which grow year round and bloom in the spring and never make a viviparous stalk. Here is a pic of the clump that I bought from Jon and Debbie that night at the Twilight Market.They reminded me of slightly swollen scallions.....I will be curious if it grows year round.