White Snakeroot

(Eupatorium rugosum)

Interesting Information About Plant:  

     Although cattle typically graze on other plants instead of white snakeroot, it was one of the only plants available when the settlers came to North America.  Since the settlers cleared out most of the trees around their settlements to build their houses, white snakeroot took advantage of the open spaces and grew abundantly.  As a result, cattle ate large quantities of the snakeroot and passed its toxin, tremetone, to humans through its milk.  Cattle develop the trembles after ingestion of the poison.  After drinking the milk from a poisoned cow, settlers would suffer from weakness, abdominal pain, and vomiting that would sometimes progress to death.  Thus, this became known as the dreaded “milk sickness.”  Even Abraham’s Lincoln’s mother died from the “milk sickness” when the Lincoln family moved to Indiana and cleared out their land to create a large farm. Native Americans used the plant to treat diarrhea and kidney stones and may have used smoke from the leaves to revive unconscious patients.  Despite its name, it is not known to cure snake bites.

Scientific Name: Eupatorium rugosum

Family Name (Scientific and Common): Asteraceae   (Aster)

Continent of Origin: North America

Plant Growth Habit: Upright Herbaceous

Height at Maturity: Between 3 – 10 Feet

Life Span: Perennial

Seasonal Habit: Herbaceous That Stays Green Through Winter

Growth Habitat: Full Sun  

Manner of Culture: Native Species

Thorns on Younger Stem: No

Cross Section of Younger Stem: Roundish   

Stem (or Trunk) Diameter: Less Than The Diameter of a Pencil

Produces Brownish Bark: No

Bark Peeling in Many Areas: No

Characteristics of Mature (Brownish) Bark: No Mature Bark (all green)

Type of Leaf: Flat, Thin Leaf  

Length of Leaf (or Leaflet): Less than Length of a Credit Card 

Leaf Complexity: Simple 

Edge of Leaf: Serrated

Leaf Arrangement: Opposite

Leaf has Petiole: Yes 

Patterns of Main-Veins on Leaf (or Leaflet): Parallel

Leaf Hairiness: Somewhat Hairy

Color of Foliage in Summer: Green 

Change in Color of Foliage in October: No Change    

Flowering Season: Summer  

Flowers: Loose Group

Type of Flower: Like a Colorful Flower

Color of Flower: White 

Shape of Individual Flower: Radially Symmetrical

Size of Individual Flower: Smaller than a Quarter 

Sexuality: Hermaphroditic Flower   

Size of Fruit: Smaller than a Quarter 

Fruit Fleshiness: Dry

Shape of Fruit: Spherical

Color of Fruit at Maturity: Green   

Fruit Desirable to Birds or Squirrels: No   

Common Name(s): White Snakeroot, White Sanicle, Indian Sanicle, Deerwort, Fall Poison, Richweed, and Squawweed

Louisville Plants That Are Most Easily Confused With This One: Thoroughwort, Hyssop-leaf Thoroughwort, Nettle-Leaved Sage and Nettle-Leaved Vervain

Unique Morphological Features of Plant: The combination of opposite, petioled leaves with coarsely serrated margins and flat-topped inflorescences of small, white flowers.

Poisonous: All of Plant

Pestiness (weedy, hard to control): No

Page prepared by:  

Alan Hall                                    

November 2004