If i remember correctly the black and white halves have been split for awhile, black half went to go kidnap some Feudal Lord farts, while white zetsu did what? and im not taking about all the dumb clones walking around i mean the real one.
Wasn't the white zetsu with Yamato? Making sure he doesn't escape and making clones under ground somewhere close to Kabuto? I could be way wrong but then again so much crap has happened, it's hard to keep track of everything. >_<