Acmella oleracea, also known under its old names Spilanthes oleracea and Spilanthes acmellaand commonly referred to as Spilanthes Extract, is a flowering herb in the plant family Asteraceae, also known as toothache plant or paracress as the leaves and flower heads contain an analgesic agent spilanthol used to numb toothache. It is native to the tropics of Brazil, and is grown as an ornamental (and occasionally as a medicinal) in various parts of the world. A small, erect plant, it grows quickly and sends up gold and red flower inflorescences. It is frost-sensitive but perennial in warmer climates.
For culinary purposes, small amounts of shredded fresh leaves add a unique flavour to salads. Cooked leaves lose their strong flavour and may be used as leafy greens. Both fresh and cooked leaves are used in dishes (such as stews) in Northern parts of Brazil, especially in the state of Pará, often combined with chillies and garlic to add flavor and vitamins to other foods. A related species is used in several Southeast Asian dishes, such as salads.
Eating a whole flower bud results in a grassy taste, followed by an extremely strong tingling or numbing sensation and often excessive saliva production and a cooling sensation in the throat. These buds are known as Buzz Buttons, Szechuan buttons, sansho buttons, and electric buttons. In India, the buds are used as flavoring in chewing tobacco.
The leaves of this plant is used by Bodo-tribals of Bodoland, Assam (India) in preparing a spicy chicken soup, mixed with other common spices. Bodos believe that this soup provides relief from cold and cough.