Hooker's sandwort

Arenaria hookeri Nuttall in J. Torrey and A. Gray, Fl. N. Amer. 1: 178. 1838

Plants densely or loosely matted, green, not glaucous, somewhat woody at base. Stems erect, 1-15(-20) cm, scabrid-puberulent. Leaves: basal leaves persistent; cauline leaves in 1-4 pairs, usually little overlapping, often larger than basal leaves; basal blades straight to arcuate-spreading, subulate to needlelike, 0.3-4 cm × 0.5-1.5 mm, flexible or rigid, herbaceous, apex spinose, glabrous, often glaucous. Inflorescences 3-30+-flowered, congested, capitate or subcapitate cymes. Pedicels 0.2-2 mm, scabrid-puberulent. Flowers: sepals 1-3-veined, often obscurely so, linear-lanceolate to lanceolate, (5-)6-10 mm, not enlarging in fruit, margins narrow, apex narrowly acute or acuminate, glabrous or pubescent; petals white, oblanceolate, 4.5-8.5 mm, ± equaling sepals, apex rounded to obtuse; nectaries as lateral and abaxial mounds with transverse groove at base of filaments opposite sepals, 0.2-0.3 mm. Capsules to 4 mm, glabrous. Seeds black, ellipsoid-oblong to pyriform with hilar notch, 1.8-2 mm, tuberculate; tubercles rounded, elongate.

Varieties 2 (2 in the flora): nc United States.