Rayless goldenrod (Haplopappus heterophyllus, previously called Isocoma pluriflora) is an erect, bushy, unbranched perennial shrub which is toxic to horses and other animals. The plant is 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.
Rayless Goldenrod Toxic Components
All parts of the plant contain trematone, which is the same toxin found in white snakeroot (Eupatorium rugosum). Cases of poisoning are sporadic due to the considerable variation in the quantity of its toxins, differing plant to plant.
- Hindlimb Weakness
- Knuckling At The Fetlocks
- Posterior Paralysis
- Acetone Odor To The Breath
- Severe Muscle Tremors
- Weakness
- Recumbency
- Respiratory Paralysis
- Coma
- 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.
