Arctic stitchwort or sandwort

Arenaria arctica Steven ex Seringe in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 1: 404. 1824; Alsine arctica (Steven ex Seringe) Fenzl; Lidia arctica (Steven ex Seringe) Á. Löve & D. Löve

Plants perennial, mat-forming. Taproots stout, woody. Stems erect to ascending, green, 3-10 cm, retrorsely puberulent or stipitate-glandular, internodes of flowering stems 2-6 times as long as leaves. Leaves tightly overlapping (vegetative) or variably spaced (cauline), usually connate proximally, with tight, scarious to herbaceous sheath 1.2-1.5 mm; blade straight to outwardly curved, green, obscurely 1-veined, linear (proximal vegetative) or subulate (cauline), rounded 3-angled (abaxial surface thickened, rounded, adaxial surface flat to concave), 5-20 × 0.4-1 mm, flexuous, margins not thickened, herbaceous, often ciliate, apex often purple, rounded to truncate, shiny, glabrous (vegetative) or glabrous to stipitate-glandular (cauline); axillary leaves absent. Inflorescences: flowers solitary, terminal; bracts narrowly lanceolate to oblong, herbaceous. Pedicels 0.5-3 cm, usually densely stipitate-glandular. Flowers: hypanthium cup-shaped; sepals prominently 3-veined proximally, lanceolate to narrowly ovate (herbaceous portion often purple, ovate to oblong), 4-8 mm, enlarging slightly in fruit, apex often purple, rounded, hooded, stipitate-glandular; petals oblanceolate, 1.5-2 times as long as sepals, apex broadly rounded, entire. Capsules narrowly ellipsoid, 9-10 mm, longer than sepals. Seeds brown, suborbiculate with radicle prolonged into beak, compressed, 1.2-1.6 mm, minutely tuberculate (50×). 2n = 22 (Russia), 26 (Russia), 38 (Russia), 52, ca. 80.

Flowering summer. Dry ridges, rocky mountain slopes, heathlands, alpine snowbed slopes, stony tundra; 0-1000 m; N.W.T., Yukon; Alaska; Asia.

Minuartia arctica is an amphi-Beringian species that is known to intergrade with M. obtusiloba. Hybrids between M. arctica and M. macrocarpa are known as well.