If this write up is correct it's ssp, evansiana that has red under the leaves..
http://www.finegardening.com/p...
Photos showing only red veins..
http://melaniesperennials.blog...
On this site it says "sometimes red on underneath"
http://www.deeproot.co.uk/pbo/...
Cruf Farm Plants will know the difference..
http://mailorder.crug-farm.co....
They have Begonia grandis 'Sapporo' which is a strain from the name place..
http://mailorder.crug-farm.co....
A pdf from Begonias.org.. it comes from China, that might be the difference, and is probably different to the species from elsewhere wherever it comes from.
http://www.begonias.org/monthl...
MOBOT.. Begonia grandis
http://www.missouribotanicalga...
Begonias.org has a list of registered Begonias, giving the parentage! These are species but the list could be useful!
http://www.begonias.org/regist...
Strange that they don't list species, but have some photos except these.
http://www.begonias.org/greenh...
Some leaf spotting on B. grandis mentioned on this site, maybe that's the difference?
http://www.rizreyes.com/Begoni...
