White Snakeroot

Latin Name: Ageratina altissima

Identifying Characteristics:

  • Grows up to 4 ft tall
  • Opposite leaves are coarsely toothed along the margins
  • White flower clusters bloom from mid-summer into fall

Plant Longevity:

  • Perennial

Where Commonly Found:

  • Open woods / wood lines
  • Semi shaded areas
  • Pastures
  • Along creeks

Time of Most Concern:

  • Green plant or when dried in hay

Compound that Causes Concern:

  • Tremetol, a fat soluble, high molecular weight alcohol
  • Crude tremetol was later shown to be separable into a toxic ketone fraction (61%) (tested in goldfish) and a sterol fraction (39%) which is nontoxic
  • Ketone fraction was later separated into tremetone, dihydrotremetone and hydroxytremetone

Part of Plant Most Toxic:

  • Leaves and stems
  • Underground parts are thought to be less toxic

Livestock Species Affected:

  • Cattle
  • Horses
  • Sheep
  • Goats

Pasture, Stored Feed, Both:

  • Both
    • Toxins can be in milk and affect the consumer of the milk (unweaned livestock and people)

Clinical Signs:

  • Stiffness
  • Depression
  • Unsteadiness
  • Anorexia
  • Sweating
  • Heart failure

Amount Needed to be Consumed for Clinical Signs / Death:

  • Consumption of 1-10% of animal’s bodyweight over a period or in one feeding
  • 10-100 lb plant material in a 1,000 lb cow

Identifying Characteristics:

  • Grows up to 4 ft tall
  • Opposite leaves are coarsely toothed along the margins
  • White flower clusters bloom from mid-summer into fall

Plant Longevity:

  • Perennial

Where Commonly Found:

  • Open woods / wood lines
  • Semi shaded areas
  • Pastures
  • Along creeks

Time of Most Concern:

  • Green plant or when dried in hay

Compound that Causes Concern:

  • Tremetol, a fat soluble, high molecular weight alcohol
  • Crude tremetol was later shown to be separable into a toxic ketone fraction (61%) (tested in goldfish) and a sterol fraction (39%) which is nontoxic
  • Ketone fraction was later separated into tremetone, dihydrotremetone and hydroxytremetone

Part of Plant Most Toxic:

  • Leaves and stems
  • Underground parts are thought to be less toxic

Livestock Species Affected:

  • Cattle
  • Horses
  • Sheep
  • Goats

Pasture, Stored Feed, Both:

  • Both
    • Toxins can be in milk and affect the consumer of the milk (unweaned livestock and people)

Clinical Signs:

  • Stiffness
  • Depression
  • Unsteadiness
  • Anorexia
  • Sweating
  • Heart failure

Amount Needed to be Consumed for Clinical Signs / Death:

  • Consumption of 1-10% of animal’s bodyweight over a period or in one feeding
  • 10-100 lb plant material in a 1,000 lb cow
Toxic Plants Home Alsike Clover Black Cherry Buttercup Carolina Horsenettle Cocklebur Common Milkweed Cressleaf Groundsel Dallisgrass Eastern Black Nightshade Hemp Dogbane Jimsonweed Johnsongrass Perilla Mint Poison Hemlock Pokeweed Redroot Pigweed Star of Bethlehem Tall Fescue White Clover White Snakeroot Yew