I had an argument one time with a guy about Tea, now when I say Tea I mean Tea not herbal tea.
He swore up and down that black teas came from different plant that green tea he was also the type that wouldn't let you prove or disprove anything and had to be right.
Black tea more or less is a fermenting/curing process that is very hard to get right.
What you have to do without rotting it is to break down the chlorophyll into starches and or sugars I think.
I am not going to look on line to make for sure.
As for green tea I cant stand the stuff.
Worth