The flowers may be solitary or may occur in clusters of 2-4. They are fragrant, 2.5-3 cm wide, with white petals and yellow anthers. In plantations the shrubs are mantained by pruning to a height of 1 to 1.5 m. Black tea is obtained from leaves allowed to ferment and then dried. During the fermentation there is an extensive enzymatic oxidation of the catechin polyphenols, producing related compounds called thea-flavins.
Oolong tea is obtained from partially fermented leaves.
Nevertheless, green tea is also used in North America and Europe. 1-3 Green tea is produced by steaming or drying the fresh leaves at elevated temperatures. This process leaves the polyphenols intact. In addition to its pleasant flavor and special aroma, green tea possesses medicinal properties that have been known since antiquity. According to traditional medicine, tea possesses stimulant, digestive, diuretic, analgesic and antitoxic properties.