Snow-on-the-Mountain, Snow-on-the-Prairie

Euphorbia marginata, E. bicolor

Euphorbiaceae (Spurge family)


Snow-on-the-mountain and snow-on-the-prairie are annual herbs in the spurge family. They generally grow to 1 to 3 feet tall. The flowering stems have a peculiar construction: a whorl of four to five petal-like members, usually yellow-green, surrounding a cluster of male flowers, each consisting of a single stamen. E. marginata leaves are long, oval and nearly hairless and come to a blunt point; the upper leaves usually have distinct white margins. E. bicolor leaves are similar but narrower.


Snow-on-the-mountain is locally abundant in Central Texas. It is somewhat uncommon in the Rio Grande Plains and Trans-Pecos regions. It also grows north to Montana and Minnesota and south to Mexico. It is found most often in tight clayey soils of swales and meadows and in dry stream beds. Populations can vary greatly from year to year. Snow-on-the-prairie is commonly found in the eastern third of Texas.

Toxic Agent

The white sap of these plants has long been used to blister the skin or as an intestinal purgative. In most cases, livestock are poisoned by an acrid principle that severely irritates the mouth and gastrointestinal tract. This plant rarely causes death. Experimental feedings of this plant in Texas have shown that 100 ounces produces severe scours and weight loss in cattle, the latter persisting for several months.

Signs of Livestock Ingestion

Primary signs include: Severe irritation of mouth and gastrointestinal tract; Diarrhea.

Management Strategies

Most species of spurge can be grazed to a limited degree without problems. Their bitter white juice apparently makes most species unpalatable. Administer intestinal astringents if needed to relieve diarrhea and intestinal wall irritation. Although most broadleaf herbicides control the plant easily, it is generally uneconomical to control as a primary target species. Proper mineral supplementation, especially of phosphorus, reduces livestock losses to the plant.