Milkweed

(Asclepias species)

Milkweed flowers, which are poisonous to horses.

Plant Description

Plants of the milkweed family (there are close to 100 different species) can vary in their appearance. There are plants in this family that have broad leaves, as well as plants that have narrow leaves.

The most notable characteristic of plants in this family is that they release a white substance very cloesly resembling milk when the plant is injured in any way.

The seeds of these plants are contained in a capusule, and contain tufts of silky material. This allows them to more easily be spread by the wind.

Flower color on the plants vary, from orange to white, and numerous other colors.

Geographic Locations

Plants in this family are found throughout the United States, usually in open, sunny areas. They tolerate various soil types, so they may be found on high ground or in river bottoms. They are often found in weedy patches along roads and field edges.

Toxic Plant Components

The narrow leaf species are more toxic than their broad leaf counterparts, but all species are toxic to some degree. The entire plant is toxic, both fresh and when it is dried. It is essential to make sure that none of these plants make it into your hay, as they often grow along the edges of fields, including hay fields.

Toxicity Cause and Symptoms

These plants are pretty toxic, with consumption as low as 0.1% of body weight (1 pound for a 1000 pound horse) capable of causing severe reactions and even death. Death usually occurs 1-3 days after consumption of the plant.

Symptoms of poisoning include:

  • Profuse salivation
  • Bloating
  • Seizures
  • Colic
  • Abnormal heart rates
  • Hypothermia
  • Death

In general, it appears that the broad leaf varieties tend to cause digestive tract problems, while the narrow leaf varieties tend to cause neurological problems.

Cure and Treatment

Treatment includes detoxifying the digestive tract, as well as supplying medical treatment to counteract heart rate problems. Sedation is often required as well.


More milkweed pictures:

Milkweed plant, which is poisonous to horses.
Milkweed plant, which is poisonous to horses.
Milkweed plant, which is poisonous to horses.
Milkweed plant, which is poisonous to horses.

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