Spilanthes is sometimes described as a medicinal plant used by Australian Aborigines where it was introduced, but it is probably used by other groups in the southern hemisphere. Native to the tropics, in the U.S., it is sometimes sold in seed catalogs as the "Eye-Ball Plant" (see photo below). Studies have shown it to have anti-bacterial, anti-viral, and anti-fungal properties and may be especially useful at early phases of certain kinds of infection and as a malaria prophylactic. It stimulates the flow of saliva, tones the gums and acts as an oral antiseptic reducing swelling, decay, and mouth sores caused by viruses. It has whole body immune-enhancing components chemically similar to those in Echinancea species and is now the subject of botanical investigation as a possible treatment against blood parasites such as those that cause Lymes disease.
Shredded and added to a mixed salad, it provides an interesting sensory experience. "It's like a trip for your tongue" says Eva, who runs the greenhouse operation at a local community college. When you chew up the leaves it is almost like there is some kind of effervescence. Of course there isn't any, but it seems like. The tingling sensation lasts a few minutes and is more profound by using the flowers and leaves.
In the tropics of Brazil, this plant is a perennial but on Long Island it is treated as a tender annual. The seeds are easily germinated in ordinary soil indoors and then transferred into the garden as pepper plants are. Given ample water and fertile compost-rich soil, Spilantes will rapidly spread producing continuous leaves and flowers through the summer and fall. The dry older flowers crumbled, release tiny seeds among the chaff (similar to lettuce) and can be stored for planting the next year. Under good conditions older stems will form adventitious roots where they contact moist soil. Cuttings with a few of these roots can be potted up and wintered over in a sunny window.