I bought some that looks just like yours in 4 inch trays last August.
The only ID included was "Bashful Bandit" with a ? mark.
I don't know if this is any help but i've noticed no one has responded yet.
Thanks for your help with the ID. I have a small collection of begonias as house plants. I have to wait for spring to be able to mail order any new ones. I've been reading the old forum posts and dreaming about new additions.