An incredibly variable species! Sometimes it is mostly pink, other times, mostly green, and sometimes it is both. Leaves are covered in velvety hairs and have a beautiful sheen to them.  This species is native to the Gunung Sinabung area in Northern Sumatra, not far from an active volcano.  From Seven New Species of Begonia from Sumatra by M. Hughes et al, 

“Begonia tuberculosa is currently known from only 2 sites, one of which (Gunung Sinabung) is being encroached despite being in the Leuser Ecosystem Conservation Area. The other site in the Gunung Leuser National Park is considered safe. It is recommended that (i) protection of the forest on Gunung Sinabung, especially at the lower elevations, be made a priority and (ii) the species be brought into cultivation.”