Polygonum (pol-ig'o-num)

Knotgra ; a genus of herbs. P. acre. 1. Smartweed; a species with a caustic juice, by some identified with P. hydropiperoides; used as an astringent and febrifuge. 2. P. hydro piper. P. bistort a. Bistort, a species common in Europe and northern Asia, and said to be found in Connecticut. The root is astringent. P. hydro piper. Water pepper; the Gr. ydropeperi of Dioscorides. The leaves or herbs were formerly employed as a diuretic and antiscorbutic, but are now chiefly used by the veterinarians as a wash for ulcers. They contain polygonic acid, have a biting and burning taste, and inflame the skin if rubbed on it. P. hydropiperoides. The mild water pepper of North America, having properties like those of P. hydro piper and sometimes used as a wash for old ulcers. [Gr., polys, many, -fgonu, the knee.]