Prickly sandwort is a loosely tufted perennial wildflower with numerous sterile stems from 2-5 cm long with flowering stems erect and rising 8-20 cm high. The mats of leaves may attain diameters up to 20 cm wide, with the central portion of older mats often consisting of dead sterile stems. The lower leaves are crowded together (See photo below.), linear, 1-2.5 cm long glaucous and persisting for several years. They are stiff and sharply pointed (a good diagnostic characteristic-- ouch!) with some minute glandular hairs on the margins. The stems bear 2-4 pairs of reduced, opposite leaves (See photo at right.) which measure up to 5 mm long, or are at most one-half the length of the lower leaves.
The inflorescence is an open cyme of a few to several flowers. The ovate sepals have obtuse to broadly acute tips with membranous margins and measure 3.5-4 mm long. They are often purple margined or purplish at the tip (See photo above.). The 5 white petals are about 1.5- 2 times longer than the sepals. The 10 ascending to spreading stamens are about as long as the petals and bear reddish to brownish anthers at their tips. The pistil typically bears 3 short styles.
Mountain Sandwort (Eremogone capillaris): The sepals are ovate with obtuse to broadly tapering to a short acute tip. Typically has lower leaves longer than 2 cm in length, softer in texture at the tips with the 2-4 pairs of stem leaves over one-half the length of the lower leaves.
King's Sandwort (Eremogone kingii): The sepals are broadly lanceolate to narrowly ovate with acute to accuminate tips. The lower leaves are over 2 cm long and and soft in texture. The 2-4 pairs of stem leaves are over one-half the length of the lower leaves, or may be nearly equal in length of the lower leaves.
Prickly sandwort is found on gravelly to rocky slopes from near 6000 feet up well into the alpine zone in the mountains.
Prickly sandwort may be found from northeastern Oregon south through the mountains of eastern Oregon to Nevada and northeastern California. It is found eastward through Idaho to western Montana.