Wild Indigo

Baptisia spp.

Fagaceae (Beech family)


Description

Wild indigo is a deep-rooted, perennial herb with bushy, branched, stout stems (often up to 3/8 inch at the base). Plants of some species may be as tall as 70 inches, but many specimens reach less than 15 inches.

The leaves are alternate with three deep lobes and two characteristic oblong structures attached at the base of the leaf stem.

The yellow or white flowers (rarely bluish) are in terminal or split spikes several inches long. In some species the spikes are erect and in others they hang like grape clusters. The fruit is a beaked pod containing two or more seeds. The dark gray or black leaf and stem color of the dead plants is a distinguishing feature of wild indigo.


Habitat

Various species of wild indigo are common in north central and eastern Texas. Texas species extend into Oklahoma, Louisiana, Arkansas and the eastern United States. They are usually found in sandy or sandy loam soil.


Toxic Agent

Alkaloids present in wild indigo are believed to be responsible for its toxicity. These plants are very unpalatable and consumption is rare except when the animal is forced to eat it in hay, as has happened with horses. There are also very infrequent reports of cattle being affected by these plants.


Signs of Livestock Ingestion

Signs of poisoning are those of a gastrointestinal upset and include: colic, diarrhea, and, anorexia.

In cases submitted to the Texas Veterinary Medical Diagnostic Laboratory, Baptisia-induced colic has been fatal to horses.


Management Strategies

Affected animals usually recover with supportive treatment after the contaminated hay has been removed. The black plant material is easily recognized in hay, which should not be fed in a manner forcing consumption.

Examine hay meadows for the plant before harvest. The individual plants can usually be removed mechanically.


Images