The fresh or dried rhizome of Phragmites communis Trin., family Gramineae.
Rhizome long-terete, the dried sample flattened, unequal in length, 1-2
in diameter; yellow-white to dull yellow in colour, the surface lustrous;
nodes obvious, with relic fibrous root scars and buds. The section is
hollow, and with a thin wall and an annular vessel pore. Sweet in taste,
cold in nature, and attributive to lung and stomach channels.
1. Clear away heat and promote the production of fluid: For febrile diseases
or those with thirst and consumption of body fluid.
2. Clear away stomach-heat and stop vomiting: For stomach-heat syndrome
with vomiting and hiccup.
3. Clear away lung-heat to relieve cough: For cough of lung-heat type
and pulmonary abscess.
4. Open the inhibited lung energy and let out the skin eruption: For common
cold of wind-heat type, and initial stage of measles with incomplete eruption.
5. Promote diuresis: For febrile disease with oliguria and reddish urine,
and stranguria of heat type.
Coixol and asparagine are two active components and possess antipyretic,
antidiptic and antemetic effects.