Family: Asteraceae (Compositae) - Aster or Sunflower FamilyNativeHerbaceous (3-15 ft)
Herbaceous (3-15 ft)Native
White Snakeroot is a herbaceous perennial in the aster family (Asteraceae) The plant is native to woodland areas in the Eastern United States and typically occurs in rich or rocky woods, thickets, wood margins, and rocky areas. The Genus name is Greek meaning 'un-aging', referring to the flowers keeping their color for a long time. The species name means 'tallest' as it is the tallest in the Genus. Native Americans used extract from the roots as a remedy for snakebite, hence the common name. White Snakeroot is easily grown in average, moist well-drained soils in full sun to partial shade. In the southeast, it will appreciate some afternoon shade. It will grow 2-5 feet tall and 2-4 feet wide. This plant can spread by rhizomes or reseeding. Deadhead spent flower heads to avoid unwanted self-seeding. Early settlers who drank milk from cows that fed on this plant often developed the disease called milk sickness and may have been the cause of death of Nancy Hanks Lincoln, mother of Abraham Lincoln. See information below for toxicity. Use in the border of cottage gardens, woodland gardens, and naturalized areas. Diseases, Insects and Other Plant Problems: Susceptible to leaf miners and flea beetles may attack the foliage.
Source: NC State Extension Gardener Plant Toolbox ↗Reconciled to full toolbox: matched by slug to slug 'ageratina-altissima'. Identity (id/common/scientific name) preserved from the original 87-plant Hunnicutt set; attribute data refreshed from the 68-attribute toolbox scrape.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Deep shade (Less than 2 hours to no direct sunlight) | Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt)
Soil pH
Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Moist | Occasionally Dry
Available space
3 feet-6 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 2 ft. 0 in. - 5 ft. 0 in. | Width: 2 ft. 0 in. - 4 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Ascending; Clumping; Erect
Texture
Medium
Foliage
Deciduous
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Opposite
Leaf shape
Cordate; Lanceolate; Ovate
Leaf margin
Crenate; Serrate
Leaf feel
Prickly
Leaf size
3-6 inches long
Hairs present
No
Leaf detail
Green leaves are up to 5 inches long and 3.5 inches across. The larger lower leaves are cordate to cordate-ovate and have more promenade veins. The smaller upper leaves are lanceolate. All leaves are hairless and have serrate to crenate margins.
Flower color
White
Flower value
Fragrant; Long Bloom Season; Showy
Flower form
Corymb
Flower shape
Tubular
Flower size
< 1 inch
Flower detail
Blooms on a terminal flat-topped corymb in late summer to fall. Each flower head is about 2-6 inches across and contains many 5-lobed, tubular disk flowers. There are no ray florets. They are densely packed creating a showy display.
Bloom time
Fall; Summer
Fruit color
Black
Fruit type
Achene
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
The fruit is often referred to as an achene but is actually a cypsela. The seeds are small, oblong, ribbed and black with a tuft of white hair. They are distributed by the wind.
Stem color
Brown/Copper; Green
Stem detail
The light green to tan stems are terete and mostly hairless.
Wildlife & Ecology
Native status
Native
Origin
Native to woodlands in Eastern United States
Distribution
AL , AR , CT , DC , DE , FL , GA , IA , IL , IN , KS , KY , LA , MA , MD , ME , MI , MN , MO , MS , NC , ND , NE , NH , NJ , NY , OH , OK , PA , RI , SC , SD , TN , TX , VA , VT , WI , WV Canada: NB , NS , ON , SK
Wildlife value
Flowers are attractive to butterflies, especially smaller species, and other pollinators, including leaf-cutting bees. Songbirds eat the seeds.
The plant is highly toxic and may be fatal if eaten. Toxicity is characterized by weakness, nausea, abdominal pain, vomiting, delirium, cardiac damage, prostration and eventually, coma. Even drinking milk from cows that have eaten the plant will cause "milk sickness" and vomiting
Toxic principle
Tremetone, a ketone, and glycosides
Contact dermatitis
No
Toxicity summary
High severity poison; parts: Flowers; Leaves; Roots; Sap/Juice; Seeds; Stems