Calyptridium pygmaeum Parish ex Rydberg in N. L. Britton et al., N. Amer. Fl. 21: 320. 1932

Plants annual, taprooted or roots fibrous. Stems 2 or more from each rosette, spreading to erect, leafy, 0.5-8 cm. Leaves basal and cauline; basal in single, prostrate rosette; blade spatulate, 0.5-1.5 cm. Inflorescences paniculate or racemose, often secund, ± dense. Flowers pedicellate; sepals ovate, 2-4 mm, fleshy, becoming membranaceous; petals persistent in fruit, 4, white, 3 mm; stamens 1(-3), anther yellow; style absent; stigmas 2; pedicel 1-3 mm. Capsules ovoid, 3-5 mm; valves 2. Seeds 5-9, black, orbicular, 0.3-0.7 mm, shiny. 2n = 44.

Flowering Jun-Jul. Dry, less often moist, sandy or gravelly soils; 1900-3500 m; Calif.