Northern Prairie Wildlife Research Center
Strictly a western plant, the easternmost collections of yellow nailwort in North Dakota are from Burleigh County. The overall range of the species is from Saskatchewan and Alberta south to Texas and New Mexico at elevations under 9,000 ft.
Yellow nailwort is a small, perennial mat-forming plant usually no more than three inches tall that resembles coarse moss. Plants have a taproot topped by a much branched stem base (caudex) at ground level. Tiny sharp-tipped leaves with white stipules are crowded along the short stems. The small yellowish flowers are numerous and lack petals, but their five yellow sepals in combination with the leaves give plants a yellowish-green color. At maturity each flower produces a tiny round fruit called a utricle. Each utricle contains a single seed.
Look for yellow nailwort from June to September on barren rocky outcrops and slopes in native grassland. More plants seem to occur where grazing is light or moderate, possibly because of trampling damage. The Paronychias are sometimes called "whitlowworts," or "nailroots." They have been used in the Mediterranean region as well as by the North American Kiowa for diuretic and aphrodisiac teas, but I found no references to such uses for the species discussed here.
Yellow nailwort is a member of the pink family (Caryophyllaceae). There are about 2,000 species in this family; many members like the carnations and campions are horticulturally important. The generic name Paronychia is the Greek name for a "whitlow" or "felon," a disease of the nails, and for plants with whitish scaly parts once supposed to cure it. The specific epithet sessiliflora means "stalkless flowers" in botanical Latin. Yellow nailwort was first described for science in 1818 by the famous naturalist, botanist, and ornithologist, Thomas Nuttall (1786-1859). Nuttall visited the Mandan villages in what is now North Dakota in 1810-1811.