Calyptridium parryi A. Gray, Proc. Amer. Acad. Arts 22: 285. 1887;C. parryi subsp. nevadense (J. T. Howell) Munz; C. parryi var. arizonicum J. T. Howell; C. parryi var. nevadense J. T. Howell

Plants annual, taprooted. Stems 2 or more from each rosette, spreading to ascending, 2-11 cm. Leaves basal and cauline; basal in single, prostrate rosette; blade spatulate, 1-3 cm. Inflorescences paniculate or racemose scorpioid cymes, becoming secund, open to dense. Flowers subsessile; sepals ovate, orbiculate, or reniform, unequal, 2-5 mm, margins scarious; petals 3(-4), white or pinkish, 1.5-3 mm; stamens 1-3, anther yellow; style absent; stigmas 2. Capsules ovoid to cylindric, 3-7 mm; valves 2. Seeds 10-15, black, orbicular, 0.6-0.7 mm, shiny. 2n = 44.

Flowering Jun-Jul. Open, sandy areas, chaparral, woodlands; 700-3400 m; Ariz., Calif.; Mexico (Baja California).

Some authorities recognize varietal segregates in this species based on minor characters that appear to exhibit much variation from population to population; they are not treated in this account.