Slender mountain sandwort

Arenaria capillaris Poiret in J. Lamarck et al., Encycl. 6: 380. 1804

Plants cespitose to somewhat matted, green or often glaucous, with woody base. Stems erect to ascending, (3-)5-20(-25) cm, entirely glabrous or glabrous proximally, stipitate-glandular distally. Leaves: basal leaves abundant, persistent; cauline leaves in 1-3 pairs, abruptly reduced distal to lowest pair; basal blades erect, straight or often curved in one direction, filiform, (2-)4-8 cm × 0.5-1 mm, flexuous, herbaceous, apex acute or acuminate to weakly spinose, glabrous, sometimes stipitate-glandular, often glaucous. Inflorescences 1-12(-18)-flowered, open or rarely subcongested cymes. Pedicels (2-)5-20 mm, glabrous or stipitate-glandular. Flowers: sepals often purplish, 1-3-veined, ovate to ovate-lanceolate, 3-4.7 mm, to 5 mm in fruit, margins broad, apex broadly rounded to barely acute, glabrous or stipitate-glandular; petals white, spatulate, 6-10 mm, 1.5-2.5 times as long as sepals, apex broadly rounded; nectaries as depressed transverse cup at base of filaments opposite sepals, 0.3-0.7 × 0.1-0.3 mm. Capsules 5-8 mm, valves at least sparsely stipitate-glandular or glabrous. Seeds brown to black, ellipsoid to ovoid with hilar notch, (1.2-)1.5-2(-2.5) mm, tuberculate; tubercles rounded, elongate.

Varieties 2 (2 in the flora): North America, Asia (Siberia).

B. Maguire (1947, 1951) and subsequent workers separated these varieties of Eremogone capillaris by sepal length: (3-)3.5-4.5(-4.8) mm in var. americana and (3.6-)5-6(-6.6) mm in var. capillaris. Material available to us did not exhibit that distinction.