Ask Mr. Smarty Plants

Mr. Smarty Plants certainly hopes that you sought medical attention before you wrote to us. What were you referring to when you wrote; "I've searched everywhere about it, but I can't seem to identify it"?

My colleagues and I here at the Wildflower Center have come up with three possible scenarios. Since this is the Wildflower Center, we'll deal with the plant part first.

There is a plant that grows in Georgia known as the Stinging Nettle Urtica dioica (stinging nettle) . It is covered with very small stinging hairs that contain formic acid  (the same formic acid that is in ant stings). Brushing against the plant releases the formic acid on the skin and causes the symtoms you described. The nettle is a fairly large plant that should be visible in your lawn. Since you implicated your flip-flop in this episode, perhaps you steped on the plant outside your lawn, and got some formic acid on the flip-flop which transfered it to your ankle with a grazing blow.

The other two scenarios exonerate plants and point to two insects as possible culprits: these are the caterpillar stages of the Southern Flannel Moth and the Saddle Back Moth. Both of these have hairs or spines that contain a venom that can be very painful when it comes in contact with human skin, but causes more serious symtoms than the formic acid. The flip-flop would play a similar role in this scenario.