Camissonia atwoodii Cronquist, Great Basin Naturalist 46: 258. 1986

Herbs annual, glandular puber­ulent. Stems several, 5–150 cm. Leaves in poorly defined basal rosette and cauline; petiole 0.7–3.4 cm; blade unlobed, broadly ovate to oblong-ovate, elliptic, or subcordate, 1.2–7.6 × 0.8–5.5 cm, margins serrulate to serrate-denticulate, brown oil cells prominently lining veins abaxially. Racemes erect, elongating in flower. Flowers opening at sunrise; buds without free tips; floral tube 0.6–1 mm; sepals 5–7 mm; petals purple, fading darker purple, 7–14 mm; stamens 4 + 4, unequal, anthers 1.5–2 mm, glabrous, stigma exserted beyond anthers at anthesis. Capsules spreading to reflexed, clavate, 11–25 mm; pedicel 3–5 mm. Seeds 1.5–1.8 mm.

Flowering Aug–Nov. Open slopes in desert shrub communities, on clay soil; of conservation concern; 1100–1600 m; Utah.

Chylismia atwoodii is known only from eastern Kane County, and only from a few collections, so is still poorly characterized morphologically, but clearly distinct among the purple-petaled species.