If you have driven around Stephens County in the last month you have undoubtedly noticed the plants with white flowers along the roads and in the fields. These native plants are about three feet tall and have light green leaves along their stems. The “flowers” are actually the white and green bracts similar to the red ones found on its cousin, the poinsettia. Bracts are specialized leaves that surround rather insignificant flowers for the purpose of attracting pollinators.

Snow-on-the-mountain (Euphorbia marginata) and snow-on-the-prairie (Euphorbia bicolor) are very close cousins that are often confused one for the other. Both plants are annuals. They do share many common characteristics but their differences are distinct. Snow-on-the-mountain typically grow in the dryer western parts of Texas including the Hill Country, but they are considered native as far north as Montana and the Dakotas and along the east coast from Maine through Georgia and Florida. In the west they grow all the way to California. About the only place they are not considered native is the Pacific Northwest. Snow-on-the-prairie are more or less limited to Arkansas, Louisiana, Oklahoma and Texas.

At one to three feet in height, the snow-on-the-mountain is somewhat shorter than its cousin, the snow-onthe-prairie, which grows from one to four feet tall. Both these plants will tolerate a variety of poor soil conditions on dry slopes, disturbed fields and roadsides. They can tolerate clay, limestone and chalky soils as well as more sandy conditions. They thrive in full sun and partial shade.

The snow-on-the-mountain is available commercially and can be grown from seeds sown in the spring or fall. The snow-on-the-prairie is not available commercially as far as I know. Both plants can be considered for wildflower beds or meadows but are not useful for forage for cattle and wildlife. It has been reported that sheep and goats can eat them with immunity. The latex secreted by the broken stems is considered poisonous and causes inflammation and blistering of the mouth, throat and esophagus in both humans and cattle. Some individuals are allergic to the sap which causes irritation of the skin, eyes and mucous membranes. Mourning doves, quail and perhaps other birds eat the seeds without being harmed.

The bracts of both plants are green with white margins or completely white. The major distinguishing characteristic between the two plants is that the bracts of the snowon-the-mountain tend to be shorter and wider whereas the snow-on-theprairie bracts are long and slender and up to four inches long and onehalf inch wide. The shorter, wider bracts of the snow-on-the-mountain make them more desirable, especially in the variegated form, to the floral trade and they are grown commercially for that purpose.

As with many native plants they self-seed readily and tend to become invasive forming large colonies that may cover many acres. Their white color lends to the appearance of being a blanket of snow, hence their name. Both plants have bloom times from July through October.

An extra caution should be noted when considering these plants for landscape uses. The latex sap can be harmful to small children. Using these plants where they can come in constant contact with pets and children should be considered with caution. It may stress the point to remember that the latex sap was used in years past to brand cattle. The sap caused irritation and blisters similar to those caused by a hot branding iron.