Fescue Sandwort, Mountain Sandwort, Slender Mountain Sandwort, Threadleaf Sandwort: Eremegone capillaris var. americana (Synonyms: Arenaria capillaris ssp. americana, Arenaria capillaris var. americana, Arenaria formosa)

The photo above shows a close-up of the flowers of mountain sandwort as seen along Cold Springs Ridge Road in the northern Wallowa-Whitman N.F.........June 26, 2008. Note the broad, whitish margins to the sepals.

Mountain sandwort is a small perennial with numerous slender rhizomes which forms loose mats or patches of plants up to 20 cm in diameter. The herbage of the stems is glabrous below and glandular-pubescent on the upper stems and amid the inflorescence. The erect flowering stems rise from 5-30 cm high. The numerous basal leaves are all narrowly linear, erect or ascending, and somewhat recurved. The basal leaves measure 2-4 cm long and from 0.5-1 mm wide. The individual leaves are somewhat flexible and soft in texture (not sharp as in Arenaria aculeata). The 2-4 pairs of stem leaves are about half as long as the basal leaves.

The flowers are found in small, open cymes at the terminus of the stems. The sepals are ovate in shape with obtuse to somewhat pointed tips and they range from 3-4.5 mm long. The sepals are also somewhat membranous-margined and purplish in color. The 5 white petals range from 1.5-2.5 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.

Prickly Sandwort (Arenaria aculeata): Typically has shorter lower leaves less than 2 cm long that are sharp-tipped with the 2-4 pairs of stem leaves short, typically less than one-half the length of the lower leaves.

King's Sandwort (Arenaria 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.

Mountain sandwort may be found from sagebrush plains to the rocky slopes at timberline in the mountains.

Mountain sandwort may be found from Alaska south in the Cascade, Olympic and Rocky Mts. to California and northern Nevada. It is found eastward to Alberta and Montana. It is also found in Eurasia.

Mountain sandwort as seen along Cold Springs Ridge Road in the northern Wallowa-Whitman N.F........June 26, 2008.

Mountain sandwort as seen at left atop Bickleton Ridge in the Bickleton Ridge Unit of the Klickitat Wildlife Area.........June 17, 2017. The photo at right shows mountain sandwort atop Spanish Peak, Ochoco National Forest.....June 17, 2019.

Close-ups of the flowers and inflorescence of mountain sandwort as seen near Colockum Pass, Wenatchee Mountains, Washington............July 7, 2012.

Mountain sandwort as seen along Forest Service Road 35 on Table Mountain, Wenatchee National Forest...........June 4, 2013.

Mountain sandwort as seen along FS Road #38-200 southeast of Spanish Peak, Ochoco National Forest..........June 14, 2015.

Mountain sandwort as seen along the last mile or so of the Wapaloosie Mountain Trail #15 in the Kettle Range, Colville National Forest..........June 23, 2016.

Mountain sandwort as seen at Blue Ridge in the Malheur NF.............June 23, 2003. Note the broad calyces with somewhat sharp to rounded tips and broad white margins. The petals are also much longer than the calyces.