According to the query, the hammer grass is a common Chinese herbal medicine in the Meixian area, also known as "wu da root", "four da root" or "giant hemp seed". It mainly grows in the mountainous areas of the stone cracks or on the soil, bitter flavor, cold, has the effect of clearing heat and detoxification, can be used to treat wind-heat colds, sore throat, carbuncles and sores and other diseases. The ring hammer grass is cylindrical, about 5-30 centimeters long, about 0.3-1.5 centimeters in diameter, with a dark brown or black surface, with obvious longitudinal grooves, hard and brittle. Its leaf blades are alternate, about 1-6 centimeters long, oblong-elliptic or elliptic, with microscopic teeth on the edges.