Tea is an infusion prepared by steeping dried leaves and twigs from the tea plant in warm water. The scientific name for the tea plant is Camellia sinensis—a shrub, one to two meters in height, containing many branches with evergreen leaves and white flowers. The leaves are about 4 cm in width and between 3 and 12 cm long and have strong ribbing. If the leaves are not dried immediately after being harvested they start to rust. In order to prevent rusting, the harvested leaves are heated to remove excess moisture.