Silverleaf nightshade_109_051805 039

Silverleaf nightshade

Solanum elaeagnifolium Cav.

Solanaceae (Nightshade family)


Description

Silverleaf nightshade is an upright, usually prickly perennial in the Potato or Nightshade family. It normally grows 1 to 3 feet tall. This plant reproduces by seed and creeping root stalks.

Its characteristic silver color is imparted by the tiny, starlike, densely matted hairs covering the entire plant. The leaves have wavy margins and are lance shaped to narrowly oblong. The showy violet or bluish (sometimes white) flowers are followed by round, yellow fruits of up to ½ inch in diameter from May to October.

The plant has poor forage value for livestock and wildlife and can be poisonous to livestock.


Habitat

Silverleaf nightshade is a serious weed of prairies, open woods and disturbed soils in southwestern United States and Mexico. It is occasionally found even farther north than Missouri.


Toxic Agent

This plant has reportedly poisoned horses, sheep, goats, cattle and humans. However, sheep and goats are more resistant than cattle, and in controlled experiments, goats were not poisoned at all. Its toxic agent is solanine. The leaves and fruit are toxic at all stages of maturity; the highest concentration is in ripe fruits. In some instances, an animal can be poisoned by eating 0.1 to 0.3 percent of its weight in silverleaf nightshade.


Signs of Livestock Ingestion

The glycoalkaloid can cause two types of effects. Nervous effects include: Incoordination; Excessive salivation; Loud, labored breathing; Trembling; Progressive weakness or paralysis; Nasal discharge.

Effects of gastrointestinal irritation include: Nausea; Abdominal pain; Vomiting; Diarrhea, sometimes with blood.

Postmortem examinations in some cases have revealed yellowish discoloration of the body fat. Plant material may be identified in rumen content of dead animals. In cases of fruit poisoning, many small, tomatolike seeds may be found between the folds of the omasum and in the abomasum.


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