One-seeded pussypaws

Calyptridium monospermum Greene, Erythea 3: 63. 1895; Spraguea monosperma (Greene) Rydberg; S. pulcherrima A. Heller

Plants perennial, taprooted; caudex unbranched (rarely branching). Stems 2 or more from each rosette, spreading to ascending, to 50 cm. Leaves basal and cauline; basal in single, prostrate rosette, blade spatulate, 0.5-15 cm; cauline leaves smaller. Inflorescences umbellate, rarely paniculate cymes, usually open. Flowers subsessile; sepals orbiculate to reniform, unequal, 3-8 mm, scarious; petals 4, rose or pinkish white to white, 3-9 mm; stamens 3, anther pink or rose; style exserted, filiform; stigmas 2. Capsules globose, 2-3.5 mm; valves 2. Seeds 1-3, black, orbicular-reniform, 0.7-1.2 mm, shiny.

Flowering Apr-Sep. Dry, sandy or gravelly soils; 300-3500 m; Calif., Nev., Oreg.; Mexico (Baja California).