Begonia 'Red Planet' is a very distinct small Begonia. The leaves of this hybrid are oval, dark green, mottled with chocolate brown and a red dot at the point of petiole attachment. It has compact growth habit. This is perfect for a vivarium. 
(MacIntyre, England, 1970)
Care of Begonia 'Red Planet':
Shade to partial shade, temp. 65-80 degrees, 4 to 6 in. tall