There is no difference in black and green tea.
Tea is made from the leaves of the Camellia sinensis plant. The difference between green and black tea comes from how they are processed after picking. Tea is a rich source of flavanoid antioxidants in the polyphenol category. Herb teas are technically not tea as most come from plants other than Camellia sinensis, so their content of flavanoids are determined by the products from which they are made. When we remove the outer fruit from black pepper, the inner seed is white pepper and when green olive ripen they become black olive, the same applies to tea. Green and black tea all come from one tea plant: Camellia sinensis. They are just processed differently. This doesn't mean all tea plants are the same. Tea is an out breeder. It has been cultivated and selected by men for thousands of years. Different cultivars are suited for making different types of teas.