Stems prostrate to ascending, 10-45 cm. Leaf blades ± ovate to spatulate, 2-8 cm, glabrous. Flowers: sepals 4-6 mm; petals 3-5 mm; stamens 3-6; pedicel usually curved in fruit, 6-20 cm. Capsules usually exceeding calyx by 3+ mm. Seeds 10-15, 1-2 mm wide, partially or totally finely tuberculate at 30×. Flowering spring. Sandy to loamy soils, disturbed places, especially burns; 20-1100 m; Calif.; Mexico (nw Baja California). Calandriniabreweri is very similar to C. ciliata. In C. breweri, the fruit usually exceeds the calyx by 3 mm or more; in C. ciliata the fruit scarcely exceeds the calyx or does so by less than 3 mm. The most consistent character separating these two species is seed surface morphology viewed at 30×: Calandrinia breweri seeds are tuberculate to some degree, whereas C. ciliata seeds have a reticulate, nontuberculate surface.