oppositeleaf spotflower, Acmella oppositifolia

Do you see any spots? I don't see any spots! One reference cites the spots on the flowers to explain their name. I suspect the name comes from a different species of the genus that has a reddish center at the top. The spot on that one stands out, and it often shows up in gardens. That species is also called toothache plant because chewing the leaves will make your mouth numb. I have been unable to find any reference to such effect with today's species, and haven't tried it. Something to keep in mind? Our spotflower grows in AL, AR, FL, GA, LA, MO, MS, NC, OK, SC, TN, and TX. Taylor Co FL, 10/20/15. Aster family, Asteraceae.