Acmella caulirhiza, commonly known as Toothache Plant, is a perennial herb native to tropical regions of Africa. It is often found in wet, marshy environments such as along riverbanks and in floodplains. This plant typically grows to a height of 15-30 cm (6-12 inches) and has a spreading habit. Acmella caulirhiza is characterized by its glossy green leaves and small, yellow, cone-shaped flowers that bloom throughout the year in its native habitat. The flowers are not particularly showy but are distinctive due to their unique shape and the tingling sensation they produce when eaten.

Toothache Plant is valued for its culinary and medicinal uses, particularly as a natural analgesic for dental pain due to the presence of spilanthol in its flowers and leaves. It is also used as an ornamental ground cover in tropical and subtropical gardens. In cultivation, it prefers moist, well-drained soils and can tolerate both full sun and partial shade. While it requires regular watering, it is generally easy to maintain. There are no widely known cultivars of this species. Gardeners should be aware that Acmella caulirhiza may spread in ideal growing conditions and should be managed accordingly to prevent unwanted spread.CC BY-SA 4.0