Chinese Tea Leaves: "Zhu Ke Cha"

"Zhu Ke Cha" translates in English bamboo wrapped tea. The wrapping contains black tea that has been compressed into small balls. Each ball is sufficient to brew one pot of tea. 

The tea plant is an evergreen of the Camellia family that is native to China, Tibet and northern India . There are two main varieties of the tea plant. The small leaf variety, known as Camellia sinensis, thrives in the cool, high mountain regions of central China and Japan. The broad leaf variety, known as Camellia assamica, grows best in the moist, tropical climates found in Northeast India and the Szechuan and Yunnan provinces of China. Tea grows mainly between the tropic of Cancer and Capricorn, requiring up to 40 inches of rain per year, as well as a temperature ideally between 50 and 80 degrees Fahrenheit, 10 to 30 degrees centigrade,.

Most tea plants have a growth phase and a dormant period, usually during the winter. The leaves are plucked as the new tea shoots (or "flush") emerge. In hotter climates, the plants have several flushes and can be picked year-round.
Source:
http://www.food-info.net/uk/products/tea/cultivation.htm
http://teapotnews.blogspot.com/search?q=zhu+ke+cha
https://qz.com/1176962/map-how-the-word-tea-spread-over-land-and-sea-to-conquer-the-world/