Queen's Delight, Trecul Stillingia

Stillingia spp.

Euphorbiaceae (Spurge family)


All three species of Stillingia in Texas are hairless, perennial herbs with milky sap and numerous shoots arising from a woody base. Two of the species are similar, with alternate, long, narrow leaves having a serrated edge and a gland in the notch of each serration. The third species has broader, more rounded leaves. Small, inconspicuous flowers appear in a spike at the end of each stalk.


One or more species grows in each vegetational area of Texas. One species can be found in loose sands, particularly in East and West Texas. The other two grow in calcareous soils of the Rio Grande Plains and the Edwards Plateau.

Toxic Agent

These plants are reported to contain cyanogenic glycosides, which release free cyanide in the rumen. They have a very low palatability and are not consumed by livestock except in extreme circumstances. Only one species, Stillingia treculiana (trecul stillingia), is a significant threat and has poisoned sheep in drought conditions.

Signs of Livestock Ingestion

Soon after consuming the plant, sheep may display clinical signs including: Salivation; Muscle tremors; Incoordination; Bloating; Bright red venous blood; Convulsions; Death from respiratory failure.

Death may occur rapidly after consumption of the plant, and most animals poisoned on pastures are found dead before clinical signs are observed.

Management Strategies

Good range management practices allowing adequate desirable forage will prevent poisoning by these plants. Sick animals will respond to intravenous administration of sodium nitrite followed by the intravenous administration of sodium thiosulfate.