A large, up to 170 cm tall, composite plant with palmately divided leaves and light reddish flowers, whose similarity to hemp gives it the name water hemp.
No recognized medicinal use, no monograph.
Both the root(Rhizoma Eupatorii cannabini) and the herb of the plant(Herba Cannabinae aquaticae) are used phytotherapeutically.
Empirical medicine: bronchitis, chronic rhinitis, colds. Also used as a mild laxative, gallbladder stimulant, diuretic and emetic, as well as a febrifuge. External: skin rashes and eczema.