Camellia sinensis. The source of the world's most popular caffeine drink, the tea plant is an evergreen shrub or small tree with glossy dark green elliptic leaves. Tea plants bloom in the autumn with fragrant, nodding cup shaped flowers about 1 in (2.5 cm) wide. The seven or eight petals are white. Native to China. Tea is a fantastic source of antioxidants. Easy to grow house plant. Harvest leaves and make into delightful rich green or black tea. Kukicha (twig tea) is also harvested from Camellia sinensis, but uses twigs and stems rather than leaves.