Begonia 'U641' is a spreading species from Laos / Thailand that offers a very dramatic "moon-speckled" type of foliage pattern. Mine seems to ramble about and with enough moisture (humidity) present, it will root at the nodes and produce both new plants as well as tubers. It doesn't seem to have a strict dormancy - so if kept warm and humid and with long days (under lights), it will grow more or less year-round. If it does go dormant (drop leaves), I'd suggest giving the tuber an 8 week drying off and then start it back up.
These plants are currently in 3" pots.
|Int - Warm||Medium|