Dense blazing star Liatris spicata
This slender perennial can get up
to four feet tall and is found in
prairies and dry soils. It has grasslike leaves that are clumped at the
base of the plant. The purplish
flowers are closely set in clusters.
The Cherokee tribe used this
species. A tea made of its root was
used to treat kidney and bladder
ailments, gonorrhea, colic, and
menstruation problems, as well as
gargled to treat sore throats. A root
poultice was used to treat
snakebites.
http://theplantencyclopedia.org/wiki/Liatris_spicata