Outsidepride Medicinal & Culinary Toothache Herb Plant Seeds - 10000 Seeds Toothache plant is used as a medicinal and culinary herb and is growin as a perennial in USDA Zones 9 - 11. This yellow flowering herb reaching 18 - 24 inches tall has a black eye in the center making it widely called eyeball plant. The yellow flowers and green leaves of toothache plant can be used in salads. The leaves/bud parts can be used in cocktails and ice dishes. Of course, there is a reason this Spilanthes is called toothache plant. The reason for the name is that when you chew on the leaves or flowers it produces a numbing effect to the tongue and gums. Sow 8 - 10 seeds per plant for a nice, full flowering plant.