White snakeroot is a shade-loving perennial wildflower native to the eastern and central United States, blooming in late summer and fall with flat clusters of fuzzy white flowers. It is poisonous: cattle that graze it pass a toxin into their milk, causing the "milk sickness" that killed thousands of 19th-century settlers.
Appearance
- Appearance
- A clump-forming perennial, usually 1–4 ft (30–120 cm) tall, with smooth, mostly hairless stems.
- Leaves
- Opposite and coarsely toothed with a sharp tip, 2–6 in (5–15 cm) long, on slender stalks. Lower leaves are broad and often heart-shaped at the base.
- Flowers
- Small, fuzzy heads of 10–30 bright white and no petals, gathered in flat clusters 2–6 in (5–15 cm) across.
- Flowering time
- July–October; one of the last wildflowers to bloom in fall.
Look-alikes
Check the leaves: white snakeroot's are broad and long-stalked, often heart-shaped at the base. White-flowered bonesets have narrower leaves and usually grow in sunny prairies and wetlands, not shady woods.
Why they get mixed upThe fuzzy white flower clusters look nearly identical, and the two were once in the same genus.
Where it lives
- Typical habitats
- Deciduous woods
- Woodland edges
- Thickets
- Shady yards and hedgerows
- Range
- Native across the eastern half of the U.S., from Maine and Florida west to Texas, and into southern Canada.
- Preferred conditions
- Partial sun to shade in moist to slightly dry soil. It often turns up as a weed in shady gardens and hedgerows.
- Flowering
Flowers Jul–Oct
Flowers Jul–Oct
Life cycle
- Seed dispersal
- Tiny seeds with fluffy white tufts drift on the wind.
Growing it
- Care
- Hardy in USDA zones 3–9. Easy in part shade and moist soil; leaves may yellow in hot, dry sun. The dark-leaved cultivar 'Chocolate' is often still sold as Eupatorium rugosum 'Chocolate'.
- Propagation
- Also spreads by underground , forming patches.
- Toxicity
- Leaves and rhizomes are highly toxic to cattle, horses, goats, and sheep. The toxin (tremetol) can pass into milk and meat. Most wild mammals avoid the bitter foliage.
Name and classification
- About the name
- Long known as Eupatorium rugosum, it was moved from the boneset genus to Ageratina. Plants of higher Appalachian elevations are sometimes treated as a variety of this species and sometimes as a separate species, Appalachian white snakeroot.
- Varieties and forms
- 'Chocolate' has purplish-brown leaves that are darkest in sun.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
Culture and stories
- Culture and stories
- Milk sickness may have caused the 1818 death of Nancy Hanks Lincoln, Abraham Lincoln's mother.
- Anna Pierce Hobbs Bixby, a frontier healer, is credited with tracing milk sickness to this plant in the 1830s.
- The name "snakeroot" comes from Native Americans' use of a root extract to treat snakebite.
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