Cressleaf Groundsel (Butterweed, Yellowtop)

Latin Name: Packera glabella (formerly Senecio glabellus)

Identifying Characteristics:

  • Starts growing as a rosette
  • Starts growing laterally in spring
  • Hollow, hairless stems
  • Daisy-like yellow petaled flowers

Plant Longevity:

  • Winter annual

Where Commonly Found:

  • No tillage row crop systems
  • Hay fields
  • Pastures
  • Moist soils

Time of Most Concern:

  • Spring

Compound that Causes Concern:

  • Pyrrolizidine alkaloids that cause chronic liver damage
    • Specifically senecionine for P. glabella

Part of Plant Most Toxic:

  • Leaves
  • Flowers
  • Seeds

Livestock Species Affected:

  • Cattle
    • 30-40 times more susceptible than sheep or goats
    • Calves and younger cattle are more susceptible than older cattle
  • Horses
  • Sheep
  • Goats

Pasture, Stored Feed, Both:

  • Both

Clinical Signs:

  • Pyrrolizidine alkaloid-containing plants can cause acute or chronic liver failure
  • Loss of appetite
  • Depression
  • Aimless walking
  • Diarrhea
  • Anorexia
  • Jaundice
  • Photosensitization (sunburn)

Amount Needed to be Consumed for Clinical Signs / Death:

  • In cattle, 4-8% of their body weight of green plant over the course of a few days can result in acute liver failure
    • 40-80 lbs per day for a 1,000 lb cow
    • Cattle that ingested 0.15% body weight (1.5 lbs plant per day in 1,000 cow) of another groundsel species for 20 days resulted in 100% mortality (chronic liver failure)

Identifying Characteristics:

  • Starts growing as a rosette
  • Starts growing laterally in spring
  • Hollow, hairless stems
  • Daisy-like yellow petaled flowers

Plant Longevity:

  • Winter annual

Where Commonly Found:

  • No tillage row crop systems
  • Hay fields
  • Pastures
  • Moist soils

Time of Most Concern:

  • Spring

Compound that Causes Concern:

  • Pyrrolizidine alkaloids that cause chronic liver damage
    • Specifically senecionine for P. glabella

Part of Plant Most Toxic:

  • Leaves
  • Flowers
  • Seeds

Livestock Species Affected:

  • Cattle
    • 30-40 times more susceptible than sheep or goats
    • Calves and younger cattle are more susceptible than older cattle
  • Horses
  • Sheep
  • Goats

Pasture, Stored Feed, Both:

  • Both

Clinical Signs:

  • Pyrrolizidine alkaloid-containing plants can cause acute or chronic liver failure
  • Loss of appetite
  • Depression
  • Aimless walking
  • Diarrhea
  • Anorexia
  • Jaundice
  • Photosensitization (sunburn)

Amount Needed to be Consumed for Clinical Signs / Death:

  • In cattle, 4-8% of their body weight of green plant over the course of a few days can result in acute liver failure
    • 40-80 lbs per day for a 1,000 lb cow
    • Cattle that ingested 0.15% body weight (1.5 lbs plant per day in 1,000 cow) of another groundsel species for 20 days resulted in 100% mortality (chronic liver failure)
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