Styphnolobium japonica

Japonica means it comes from Japan (you probably knew that, though).

The word Styphnolobium explains the traits that help identify the tree. Much of it has to do with the shape of the flowers and position of the leaves on the stalk, Here is a definition better written than I could do myself. :

http://www.wordiq.com/definition/Styphnolobium

very interesting !

I think it consists of two Greek words, but which and which are
their meaning?