Identification
This native annual plant grows 1-3 feet tall. The alternate oval leaves are up to 4 inches long and 2 1/2 inches wide. Leaves have smooth green or variable white margins. At the top of the plant there are typically 3 clusters of flowers rising above a whorl of modified leaves (bracts) that have showy white margins. The much less conspicuous “flower heads” or floral cups are less than 1/2 inch in diameter and consist of 4 (sometimes 5) irregularly spaced white, petal-like bracts around a solitary female and several male flowers which have no petals. As the plant matures, a hairy, 3-lobed seed capsule on a stout stem rises from the center of the “flower”.
This Great Plains native prefers sunny dry sites. It is often common in overgrazed pastures because the toxic, irritating milky sap causes livestock to selectively avoid it. Snow-on-the-Mountain is rare at Neale Woods where it occasionally occurs in sunny areas of disturbance in prairie restorations or old fields. There are no recent records from Fontenelle Forest. Flowering occurs from July through September.
Snow-on-the-Mountain has been widely planted as a garden ornamental because of its attractive foliage. It is closely related to our popular Christmas plant, the Poinsettia whose showy modified leaves known as bracts are red rather than white. The specimen has been lost, but a description by Meriwether Lewis indicates he collected this plant near present day Blair, Nebraska, only a few miles north of Neale Woods, on August 4, 1804.
Other common names include Variegated Spurge, Wolf’s Milk and Mountain Snow.
The content of NatureSearch is provided by dedicated volunteer Naturalists of Fontenelle Forest who strive to provide the most accurate information available. Contributors of the images retain their copyrights. The point of contact for this page is: Neal Ratzlaff.