When I was walking my dog at Cooper Park recently, I saw this plant in front of the Shot Gun Cabin that I had never seen before. Of course I had to take a closer look. I thought it was lovely so I looked it up when I got home. It is native to Texas, New Mexico, Oklahoma, Missouri and Arkansas.
by Dorothy Thetford
COMMON NAME: Snow-on-the-Prairie
BOTANICAL NAME: Euphorbia bicolor
Snow in September? On a prairie? In Texas? Sure....
Our native wildflower, commonly called snow-on-the-prairie Euphorbia bicolor, attracts attention to the hot, dry prairie with its cool, green and white bracts. These three to four-inch bracts are longer than the leaves of the plant, and completely dominate the tiny white flower structures.
Actually, the white structure is not a flower, but a cyathium (the specialized inflorescence of Euphorbia, consisting of a flower-like, cup-shaped involucre which carries the several true flowers within) as defined by M. Enquist in his book WILDFLOWERS OF THE TEXAS HILL COUNTRY.
Each 5-petaled structure, only 1/4 inch diameter, looks like it's been tucked into the base of the bracts as an afterthought, almost hidden by the long, wispy bracts.
Snow-on-the prairie is a single, stout, hairy, 3 to 5-foot stem which splits, midway up the stem, into a perfect triangular set of (three) branches. With ample moisture, these three branches may grow 6 to 10 inches taller and split into additional sets of three branches.
One to two-inch, hairy, lanceolate, alternate leaves line the stem up to the first branch split, and at that point, three opposite leaves encircle the base of the split. This interesting leaf arrangement is repeated with each new symmetrical branching.
A milky latex weeps from any broken stem, leaf or bract. All Euphorbias contain this milky sap, which can cause dermatitis to sensitive-skinned persons, and, is toxic. Since livestock does not eat this plant, snow-on-the-prairie is normally found in very large colonies throughout the Grand Prairie, Blackland Prairie, east to east Texas, and from Montague County southwest to Johnson County. A single plant is intriguing, but a colony is breathtaking.
As flowers mature, green, hairy, 3-seeded capsules develop and stay on the plant until they dry, harden, pop open and disperse seeds. This ballistic dispersal of seeds explains the scattered arrangement of plants on the prairie. If you plan to collect seeds from this annual, you must monitor the maturity and collect after the pod dries, but before it pops open.
Texas Woman's University, under the direction of our Trinity Forks member, Camelia Maier, Ph.D., Associate Professor in the Biology Department, is currently researching E. bicolor to identify the chemical composition of estrogens within the plant for future medicinal purposes.
Our sunny prairies and roadsides are extremely enticing with this grande native wildflower. While E. bicolor is in full bloom, take time to touch the leaves, and, use a magnifying lens to closely inspect the downy-soft, hairy details of this uniquely beautiful wildflower. I think you'll appreciate having snow-on-the-prairie, especially in Texas during the heat of August and September!