Dim sum various mixtures of flowers with green tea, black tea or oolong tea. Flowers used include jasmine, gardenia, magnolia, grapefruit flower, sweet-scented osmanthus and rose. There are strict rules about the proportion of flowers to tea. Jasmine tea is the most popular type of scented tea, and is often the most popular type of tea served at yum cha establishments. The above teas are produced in most of China. Chinese tea bushes ("Camellia sinensis") are cultivated in the mountain areas of tropical and subtropical regions or wherever there is a proper climate, sufficient humidity, adequate sunshine and fertile soil. Chinese tea
Camellia sinensis catalyzes the conversion of 7-methylxanthine to theobromine, as well as the final conversion of theobromine to caffeine. Camellia sinensis Camellia sinensis is a species of evergreen shrub or small tree whose leaves and leaf buds are used to produce tea. It is of the genus "Camellia" () of flowering plants in the family Theaceae. Common names include "tea plant", "tea shrub", and "tea tree" (not to be confused with "Melaleuca alternifolia", the source of tea tree oil, or "Leptospermum scoparium", the New Zealand Tea Tree). "Camellia sinensis" var. "sinensis" and "Camellia sinensis" var. "assamica", are two major varieties grown today.