PLANT: Shrub, profusely branched, thorny, 1–3.5 m tall, with glandular pubescence and silvery to dark gray or brown bark. LEAVES: obovate-spatulate or elliptic, 1–4 in a fascicle, 3–12 mm long, 1–5 mm wide, rounded to obtuse at apex; petiole indistinguishable from the lamina, densely pubescent, sometimes cinereous. FLOWERS: erect, borne singly or in pairs, pedicels 2–10 mm long, pubescent; calyx campanulate, densely pubescent, tube 2–3 mm long, lobes 5, elliptic or oblong-oval, apex rounded to acute, half as long as or longer than the tube; corolla with greenish purple throat externally, tube narrowly campanulate to narrowly obconic, contracted above the ovary, 6–10 mm long, 2–3.5 mm broad at the throat, lobes 5, pale lavender, with darker lavender marks, spreading, ovate, 2–3 mm long, with ciliolate margins; stamens exserted due to spreading of the corolla-lobes, about equalling them in length; filaments adnate to lower half of corolla-tube, densely pilose on lower fourth of free portion; style equalling stamens. FRUITS: red, ovoid, 4–7 mm long, 3–5 mm thick, 7–15-seeded (Fig. 2I). n = 12. NOTES: Washes, alluvial fans in Sonoran Desert; La Paz, Maricopa, Mohave, Pima, Pinal, Yavapai, Yuma cos. (Fig. 1H); 250–1200 m (800–3900 ft); Feb–Sep; CA, NV; Son., Baja C., Mex. REFERENCES: Windham, M.D. And G. Yatskievych. 2009. Vascular Plants of Arizona: Isoëtaceae. CANOTIA 5 (1): 27–29, 2009.