PLANT: Annual, 6-30 cm tall, simple or with 1-5 widely spaced, dichotomous branches above the base, glabrous. LEAVES: mostly simple, sometimes with 3 lobes, linear, 1-3.5 cm long, glabrous. INFLORESCENCE: open, the flowers 1-3, axillary and terminal. FLOWERS: sessile to subsessile; calyx glabrous, narrowly campanulate, 8-13 mm long, the lobes equalling the tube, the hyaline membranes usually wider than the herbaceous ribs; corolla nocturnal, closed during the day, funnelform, 8-16 mm long, white to cream, the lobes tinged with purple; stamens inserted on the upper tube; filaments glabrous; style included. 2n=18. NOTES: Sandy to rocky soils, washes and bajadas, desert shrubland and woodland; Coconino, Gila, Graham, La Paz, Maricopa, Mohave, Pima, Pinal, Santa Cruz, Yavapai, Yuma cos.; 60-1400 m (200-4600 ft); Feb-May; s CA to s UT. REFERENCES: Dieter H. Wilken and J. Mark Porter, 2005, Vascular Plants of Arizona: Polemoniaceae. CANOTIA 1: 1-37.