Acmella repens

Acmella repens, sometimes called creeping spotflower or oreja de ratón, is a low-growing perennial herb in the Asteraceae family native to the Americas, with a broad distribution from the southern United States and Mexico through Central America to South America and the Caribbean. It is a creeping to ascending plant with succulent, often reddish stems that root readily at the lower nodes and reach 10 to 40 cm in length. The leaves are opposite, simple, ovate to lance-ovate, 2 to 7 cm long, with shallowly toothed to crenate margins, three prominent veins from the base, and a soft, slightly pubescent surface. Flower heads are solitary on long peduncles, ovoid to conical, 8 to 15 mm long, with a central dome of yellow to orange-yellow disc florets and short, often inconspicuous yellow ray florets (4 to 8 in number); the receptacle is conspicuously elongate at maturity. Like its close relative A. oleracea (the toothache plant), the heads produce N-isobutyl alkylamides (spilanthol) that cause a tingling, numbing sensation when chewed. (POWO; Flora Mesoamericana)