The toothache plant (Acmella oleracea) is a flowering plant native to Brazil. It has many names, including:
 
Spilanthes acmella
jambu
electric daisy
paracress
eyeball plant
The plant is related to the daisy, but it looks very different. It has round, yellow flowers with dark red spots in the center. These flowers, often called buzz buttons or Sichuan buttons, are actually clusters of many tiny flowers.