Brazos County Herbarium

Brazos County Horticulture Extension

Texas Groundsel, Texas Squaw-Weed

Senecio ampullaceus

Description

Texas groundsel is a cool-season annual herb. It grows to 12 to 30 inches tall. The plants are often whitish with hair, but can be nearly hairless. The unlobed, clasping leaves gradually reduce in size toward the top of the plant. Showy yellow flowers are produced in the spring. The seedling, or winter rosette, often has a purplish cast to the underside of the leaves, especially on the midrib.

Habitat

Texas groundsel is found in the eastern half of the state. It is abundant in sandy soils and may be a predominant species in freshly cleared forest.

Toxic Agent

The toxic agent of these plants has not been established, nor have experimental feeding trials proven its toxicity. In field cases, cattle consuming Texas groundsel developed clinical signs and lesions typical of pyrrolizidine alkaloid poisoning, as occurs with other Senecio species. Clinical signs appeared several months after it was ingested; the plants were long dead when the animals became ill. The dead animals had classical liver cirrhosis identical to that produced by pyrrolizidine alkaloids. Tests on many normal-appearing herd mates of the dead animals showed that they also had liver damage. Llamas pastured with the plant for months at a time have also succumbed to terminal liver cirrhosis.

Signs of Livestock Ingestion

The clinical signs of poisoned cattle and llamas may include: Anorexia; Depression; Weight loss; Aggression; Death.

These animals die because of liver failure.

Management Strategies

Cattle are more likely to consume the young plants while they are still in the rosette form in late fall and winter. Poisonings during this period can be reduced by providing adequate hay and supplemental feed. Because llamas seem to be either more sensitive to the plant or less selective grazers than cattle, eliminate the plants from their pastures. Sheep tolerate a greater intake of pyrrolizidine alkaloids than other animal species and may be used to remove the young plants. Heavily infested pastures may be treated with broadleaf herbicides such as 2,4-D or Grazon P+D®.

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Department of Rangeland, Wildlife, and Fisheries Management

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