It’s even better than I thought.
Begonia amphioxus is an interesting plant to look at. With narrow leaves and bright reddish spots, it is worth having in your collection. We just need a good common name.
The one I have at the North window does fine with no additional humidity needed.
But here is how it’s better.
I went on vacation, and it was not watered for 12 days. When I got back, it was very dry but suffered no damage --- no brown leaves or leaf drop. The slight wilt perked up with water.
Begonia amphioxus is the perfect houseplant. Everybody should have one.