It certainly does look like Begonia concinna! It's a pity there's no shots of the flowers.
I found it on Tropicos but there's no images.
http://www.tropicos.org/Name/5...
I searched the reference it's published in, tried to translate but got the same so it must be ancient latin.
http://archive.org/stream/syst...
I can understand most of the wording, e.g. "foliis peltatis oblique" means foliage is peltate and oblique.
The original book ..
http://www.biodiversitylibrary...
54. Begonia concinna Schott. B. acaulis, foliis peltatis oblique el-
lipticis acuminatis integerrimis utrinque pilofis,
florum cf petalis exterionbus orbiculatis, fructuum
alis bitns fubparallelis rotundatis , tertia maxima
obtura.
Reference on Kew ..
http://apps.kew.org/wcsp/qsear...
Links ..
http://www.bgci.org/plant_deta...
Botanic Garden and Botanical Museum Berlin-Dahlem, Freie Universität Berlin (B), B 10 0366048 (drawing and fragments but don't have permission to enlarge).
http://plants.jstor.org/stable...
