I had found some research material stating that this one is from an unknown origin but suspected could be a Venezuelan species given as by a Japanese visitor to a US botanist. Hence the trail of origin history is vague. Perhaps it could also be that these would had spread out around the South Asia Region among collectors without much of it's identity categorised.
This Burgundy like coloration appears more vividly when exposed to more bright light - I had found the nice green tones appears when grown in shade - these appear to be more shrub like and and the leaves appear very fragile. It has a fine furry surface on the plant structure.
Based on my opinion, I find this very similar like a Burning Bush Begonia especially the foliage coloration and structure - however, like most begonia where their point of origin can be very challenging and in question - a lot of research and study is required.
Begonia Common Names and Images
Do click on the Link Above ☝
Here is the link where I had put together a list of all the begonias that I had come across. A database of all the different types & their characteristics. Please click on the link on the title above for the post.