Native Americans used horsetail as a poultice to promote wound healing. The Thompson tribe in British Columbia applied the ashes of horsetail fern stems to burns. The herb's high silica content makes it abrasive, and in the past it was used to polish metal and wood. Its common name, bottlebrush, indicates another of its uses. Horsetail was also tied to the tails of livestock to Enhance them ward off flies. It was long considered a wound-healing herb.