1. Spergularia macrotheca (Hornemann ex Chamisso & Schlechtendal) Heynhold, Alph. Aufz. Gew. 689. 1846.
Arenaria macrotheca Hornemann ex Chamisso & Schlechtendal, Linnaea 1: 53. 1826
Plants strongly perennial with branched, woody base, stout, 5-40 cm, densely stipitate-glandular in inflorescence or throughout. Taproots becoming stout, woody. Stems erect or ascending to prostrate, usually branched proximally; main stem 0.8-3 mm diam. proximally. Leaves: stipules conspicuous, dull white to tan, narrowly triangular, 4.5-11 mm, apex long-acuminate; blade linear, (0.6-)1-5.5 cm, fleshy, apex apiculate to spine-tipped; axillary leaves 1-2+ per cluster. Cymes simple to 3-compound or flowers solitary and axillary. Pedicels erect, divergent, or reflexed in fruit. Flowers: sepals connate 0.5-1.8 mm proximally, lobes often 3-veined, ovate to lanceolate, 4.5-7 mm, to 8 mm in fruit, margins 0.3-0.7 mm wide, apex blunt to rounded; petals white or pink to rosy, elliptic to obovate, 0.9-1.3 times as long as sepals in flower; stamens 9-10; styles 0.6-3 mm. Capsules tan, 4.6-10 mm, 0.8-1.4 times as long as sepals. Seeds ± red-brown, often with submarginal groove or depression, suborbiculate to pyriform, compressed, (0.6-)0.7-1.2 mm, smooth to faintly or prominently tuberculate or sculpturing of parallel, wavy lines or of low, rounded mounds, not papillate; wing absent or white to reddish brown proximally, 0.1-0.3 mm wide, margins irregular.
Varieties 3 (3 in the flora): w North America, including nw Mexico.