There are not very many plant families that have milky sap. Milkweeds certainly come to mind, as well as some members of the aster family such as the dandelion and western salsify. The spurge family also produces milky sap and includes a few species native to North Dakota and some other noteworthy species.
A dozen species
There are about a dozen species of spurges that may be found in North Dakota, most of which go largely go unnoticed.
Leafy spurge (Euphorbia escula) is the most widely known spurge in the state. This exotic invader has been the bane of natural resource managers for decades. It is listed as a noxious weed in the state, and like many noxious weeds was introduced to North America as an ornamental.
If you are a gardener, you are likely familiar with a member of the spurge family. Have you had to pull or hoe a small, prostrate, spreading garden weed that bleeds white? If so, that is thyme-leaved spurge or a close relative. Snow-on-the-mountain (Euphorbia marginata), a native to the Midwest has also been documented in a few counties in North Dakota and is occasionally used as an ornamental. It should be noted, however, that it is not the snow-on-the-mountain used in border plantings (Aegopodium podagraria “variegatum”) which is a member of the Apiaceae or parsley family.
Poinsettias
It might surprise you, but the poinsettia is a member of the spurge family. It is a shrub native to Central America and is named after Joel Poinsett, the first U.S. ambassador to Mexico. The colorful bracts (usually red or cream colored) are quite showy.
The flowers however, are actually the small yellow structures in the center of the cluster of the bracts. Rather than throwing out your poinsettia after Christmas this year, consider keeping it. They are easy to grow and make for an interesting house plant. And with a little extra care can produce an even larger and showier plant next Christmas.
