Northern Prairie Wildlife Research Center
The northernmost collections of annual eriogonum are from southwestern North Dakota and eastern Montana. In North Dakota, plants are restricted to the area west of the Missouri River. Elsewhere, the species ranges south to Texas and Mexico at elevations under 7,000 ft.
Annual eriogonum is an annual or sometimes biennial forb from a slender tan taproot. Plants grow up to 40 inches tall, but are usually about two feet tall in our area. Stems are usually simple. Stems, branches, and leaves have a dense covering of short, silvery-gray hairs. A tuft of small leaves grows at the base of the stem, but these leaves soon wither. Numerous club-shaped leaves overlap along the lower half of the plant. These leaves are about two inches long, 1/2-inch wide, and some bear rounded teeth. Flower clusters about 1/8 inch wide form at the tips of the branches. The tiny flowers are whitish, sometimes with a tinge of pink. Fruits are tiny, smooth achenes.
Look for annual eriogonum from July through September on dry, sandy or gravelly native prairie where grazing pressure is not extremely intense. This may be the plant the Lakota called "i'hiyan peju'ta" (to make the mouth breathe better). Children with sore mouths and "those who cannot urinate well" were given a tea made from this plant.
Annual eriogonum is a member of the smartweed family (Polygonaceae) that contains about 30 genera and 900 species. Buckwheat and rhubarb are the only economically important species. The genus Eriogonum (from the Greek erion "wool" and gonu "knee or joint") was compounded to refer to the heavy pubescence and swollen joints found on many species in this group. There are nearly 200 species in the genus, sometimes called "umbrella plants" because of the shape of the inflorescences. All species are native only to America and are best developed in the southwest. The specific epithet anuum means "of the annuals" in botanical Latin. Annual eriogonum was described for science in 1837 by the distinguished English-American naturalist Thomas Nuttall (1786-1859. In 1811, Nuttall ascended the Missouri to what now is North Dakota.