Did anyone ever contact you with an answer to this rare begonia question?
I an also looking for the same plant although we called it a turkey claw
Closest thing I can find is a begonia gryphon. It was the same shape but covered in red hairs on the stem and leaves.
Thank you for contacting Toronto Master Gardeners about the “Turkey Paw” begonia. Below is a link to the TMG answer given for the original question and it seems that the only similar plant, without the maple shaped leaves, would be the Tiger Paw begonia.
Your suggestion of the Gryphon Begonia is a good one. The plant has maple shaped leaves and in the link below, there are many colour combinations. It would certainly add interest to an indoor plant collection or as a container plant in the summer. Thanks for your contribution to the rare begonia search for the illusive “Turkey Paw”.