Acmella is a genus of thirty species of plants in the daisy family

Asteraceae

The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...

. It is native to the Americas, from the southern United States to South America (and areas in between), and also has been introduced to Asia, Africa, Pacific islands, and Australia. It includes the species Acmella oleracea

Acmella oleracea

Acmella oleracea, also known under its old names Spilanthes oleracea and Spilanthes acmella and 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...

(toothache plant), cultivated worldwide for medicinal, insecticidal, and gardening purposes.

Selected species

• Acmella ciliata
• Acmella oleracea
  Acmella oleracea
  Acmella oleracea, also known under its old names Spilanthes oleracea and Spilanthes acmella and 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...
  
  (L.) R.K.Jansen
• Acmella oppositifolia (Lam.) R.K.Jansen
  • Acemlla oppositifolia var. oppositifolia - Mexico, Central America, and northern South America
  • Acmella oppositifolia var. repens (Walter) R.K.Jansen - southeastern United States. Sometimes treated as its own species Acmella repens.
• Acmella uliginosa (Sw.) Cass.
• Acmella paniculata (Wall. ex DC.) R.K.Jansen
• Acmella pusilla - South America
• Acmella sodiroi (Hieron.) R.K.Jansen