Green tea is claimed to have been popularized in Japan around 1190, when a Zen priest visiting and studying in China’s great Buddhist monasteries and temples returned to Japan with tea plant seeds and bushes. The young priest, called Eisai, used his experience growing and drinking tea in China to popularize the way of tea as a meditation ritual within his own community of Buddhist monks, eventually spreading the custom of tea drinking throughout the rest of Japan. To this day, China and Japan are the top two green tea producing and exporting countries in the world.
Japanese green teas have a thin, needle-like shape and a rich, dark green color. Unlike Chinese teas, most Japanese teas are produced by steaming rather than pan firing. This produces their characteristic color, and creates a sweeter, more grassy flavor. A mechanical rolling/drying process then dries the tea leaves into their final shape.[54] The liquor of steamed Japanese tea tends to be cloudy due to the higher quantity of dissolved solids.[56]
In China though, the term black tea or dark tea typically refers to a tea that we call Pu-erh in the United States. This tea is fermented anywhere between 2 weeks to two months and then aged for 2 months to 20+ years in order to create dark black leaves and a dark color to the brew. In this fermentation process the leaves are intentionally kept damp to encourage good microbes and bacteria to slowly oxidize and ferment the leaves. This is distinguished from red tea which typically only takes about 6-10 hours to oxidize. Pu-erh tea typically has a strong fermentation taste but high quality pu-erh should not taste overly earthy as this is a sign of low quality production techniques.

Although numerous claims have been made for the health benefits of green tea, human clinical research has not provided conclusive evidence of any effects.[2][7][11] In 2011, a panel of scientists published a report on the claims for health effects at the request of the European Commission: in general they found that the claims made for green tea were not supported by sufficient scientific evidence.[7] Although green tea may enhance mental alertness due to its caffeine content, there is only weak, inconclusive evidence that regular consumption of green tea affects the risk of cancer or cardiovascular diseases, and there is no evidence that it benefits weight loss.[2]
Another benefit of green tea it’s is lower in caffeine than most other teas, so you may be able to drink the five cups a day that lowered psychological stress in a large group of Japanese people in a recent study done at Sendai’s Tohoku University Graduate School of Medicine. The researchers didn’t identify any particular component of green tea that might have been soothing, but animal studies suggest that one compound, EGCC, had both sedative and hypnotic effects that tamp down the body’s production of stress chemicals.
In 1994, Burke International registered the name "Rooibos" with the US Patent and Trademark Office, thus establishing a monopoly on the name in the United States at a time when it was virtually unknown there. When the plant later entered more widespread use, Burke demanded that companies either pay fees for use of the name, or cease its use. In 2005, the American Herbal Products Association and a number of import companies succeeded in defeating the trademark through petitions and lawsuits; after losing one of the cases, Burke surrendered the name to the public domain.[13]