Ageratina altissima - (L.)R.M.King.&H.Rob.
Common Name White Snakeroot, Richweed
Family Asteraceae or Compositae
USDA hardiness 5-9
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].
Habitats Low woods in river valleys in Texas[274].
Range Eastern N. America.
Edibility Rating  
Other Uses  
Weed Potential Yes
Medicinal Rating  
Fully Hardy Moist Soil Semi-shade Full sun

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Ageratina altissima White Snakeroot, Richweed

Ageratina altissima White Snakeroot, Richweed
Physical Characteristics
 icon of manicon of flower
Ageratina altissima is a PERENNIAL growing to 2 m (6ft 7in).
It is hardy to zone (UK) 6. It is in flower from Aug to September. The flowers are hermaphrodite (have both male and female organs) and are 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: acid, neutral and basic (alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Eupatorium ageratoides. E. rugosum. E. urticaefolium,

Woodland Garden Sunny Edge; Dappled Shade;
Edible Uses
None known
Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.

Diaphoretic;  Diuretic;  Febrifuge;  Odontalgic;  Stimulant;  Tonic.

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].


Other Uses
None known
Cultivation details
Succeeds in an ordinary well-drained but moisture retentive garden soil in sun or part shade[200]. There is some difference of opinion over the correct name for this species with some authorities using Eupatorium rugosum[K].
Seed - sow spring in a cold frame, only just covering the seed. When large enough to handle, prick the seedlings out into individual pots and plant them out in the summer. Division in spring.
Other Names
Found In
Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Conservation Status
IUCN Red List of Threatened Plants Status : This taxon has not yet been assessed.
Related Plants


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Botanical References
Links / References
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Readers comment
billy leung   Wed Jan 12 21:41:23 2005
i believe the information on this species, Eupatorium rugosum or Ageratina altissima, is mistaken in that it is a poisonous species. According to some literature, Abraham Lincoln's mother died of poisoned milk from affected animals. I think it is well documented in lots of places.
Bryan French   Fri Jul 13 2007
The habitat is more exensive than "Low woods in river valleys in Texas." Ageratina altissima's native habitat are the wooded lowlands of the Appalachian Mountains from southern Quebec to northern Georgia.
eibren   Fri Jun 5 2009
It seeded itself along the edge of a new planting in my garden in South Central Pennsylvania, USA; apparently the birds like the seeds.

Veterinary Medicine Library More information on effects of toxicity

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Subject : Ageratina altissima  

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