nitrates tremetone dehydrotremetone 6-hydroxytremetone 3-oxyangeloyl-tremeton
Flower Color:
  • flower color
wasteareas, fields, pastures, roadsides

Time of Greatest Risk


Geographical Distribution

Rayless Goldenrod distribution - United States

Related Species

Rayless Goldenrod

Isocoma pluriflora

Southern Goldenbush, Southern Jimmyweed
7/ 10
Rayless Goldenrod toxic components horses
Rayless goldenrod (Isocoma pluriflora) is an erect, bushy, unbranched perennial shrub that's native to the Southwestern United States and Northern Mexico. It has narrow leaves and clusters of yellow flower heads at the top of the stems, each head with 8 to 21 yellow disc flowers.

Toxic components
I. pluriflora is toxic to all livestock, causing a condition known as trembles. Daily consumption of only 1-1.5% of an animal's body weight for a week or more can poison the animal which could potential lead to its death. Poisoning is sporadic due to the considerable variation in the quantity of its toxins, which research suggests are benzofuran ketones (tremetone, dehydrotremetone, 6-hydroxytremetone, and 3-oxyangeloyl-tremeton).


  • Trembling (especially After Exercise)
  • Incoordination
  • Shaking
  • Stiffness
  • Reluctance To Ear
  • Altered Posture (they Take An Arched Back Position)
  • Dribbling Of Urine
  • Labored Breathing
  • Depression
  • Colic
  • Lethargy
  • Death


CHEMICAL CONTROL: Picloram (0.5 lb/ac) applied in the fall after bloom and before frost. Picloram (1%) spray to wet; applied in the fall after bloom before frost. Tebuthiuron (1.0 lb/ac or 1/2 oz/plant) applied in the summer before rainfall.