It is the fresh or dry rhizome of Phragmites communis. You can dig all year round to remove buds, fibrous roots and membranous leaves, and use them fresh or dry them in the sun.

Removing impurities, cleaning, cutting or drying after cutting.

(fresh reed root): long cylindrical, some slightly flat, different in length, with a diameter of 1 ~ 2 cm. The surface is yellow and white, shiny, the epidermis is loose and peelable, the nodules are annular, and there are residual roots and bud marks. Light weight, tough, not easy to break. The section is yellow and white, hollow, with a wall thickness of 1 ~ 2mm, and the holes are arranged in a ring shape. Odorless and sweet.

(dry reed root): it is oblate cylindrical. Nodes are hard and there are longitudinal wrinkles between nodes.

Sweet and cold in nature. Enter the lung and stomach meridians.

Functions: clearing away heat, promoting fluid production, relieving restlessness, stopping vomiting and inducing diuresis. Used for fever, polydipsia, vomiting due to stomach heat, cough due to lung heat, purulent lung abscess, heat stranguria and astringent pain.