White Snakeroot, Richweed

Ageratina altissima

Physical Characteristics

Ageratina altissima is a PERENNIAL growing to 2 m (6ft 7in). See above for USDA hardiness. It is hardy to UK zone 6. It is in flower from August to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. The plant is self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Distribution

Eastern N. America.

Habitats

Woodland Garden Sunny Edge; Dappled Shade;

Edible Uses

None known

Medicinal Uses

Diaphoretic Diuretic Febrifuge Odontalgic Stimulant Tonic Urinary The root is diaphoretic, diuretic, febrifuge, stimulant and tonic[257]. It has been used in the treatment of diarrhoea, gravel and urinary diseases[257]. It has also been used in herbal sweat baths to encourage sweating[257]. A decoction or infusion of the root has been taken to treat a fallen or inflamed womb[257]. The root has been chewed and held in the mouth as a treatment for toothache[257].

Known Hazards

The plant contains tremetol, a complex alcohol, and glycosides. These toxins cause a fatal disease known as 'staggers' in cattle. The toxin can be passed through the milk and has caused fatalities in humans who have drunk affected cow's milk[274].