PLANT: Shrub 0.6–2 m tall, stout, densely branched, thorny, the branches thick and rigid, silvery to purplish or tan to reddish when old, minutely glandular-puberulent when young. LEAVES: 3–10 in fascicles, spatulate, oblanceolate, or obovate-spatulate to broadly obovate, 1–3.5 cm long, 0.4–1.3(–2.3) cm wide, densely glandular-pubescent or hispidulous to glabrescent; apex rounded to truncate; base attenuate; midvein and some of the lateral veins distinct. FLOWERS: numerous, pendant, 1–3 in a fascicle, the pedicels about the same length as the calyx or shorter, glandular-pubescent; calyx bowl-shaped or oblong-campanulate, 4–14 mm long, glabrate or glandularpubescent, expanding and usually rupturing with the growth of the fruit (Fig. 2E); corolla greenish white with purple veins, broadly funnelform to nearly cylindric, slightly expanded at top, densely pubescent to glabrous externally, the tube 8–15 mm long, the lobes 5, 1/4 to 1/5 the length of the tube, triangular-ovate, spreading or reflexed, with margins usually ciliate; stamens about equalling the corolla-tube or slightly included; filaments subequal, adnate from about middle of corolla-tube to about 3/4 the length; vascular strands leading to filaments very sparsely pilose at the base, the free portion of filaments glabrous; style shorter than filaments or equalling them. FRUITS: ovoid, greenish yellow, 5–10 mm long, constricted at about the middle or above; seeds 1–2 in upper portion, several (5–8) in lower half. n = 12. FRUITS: ovoid, greenish yellow, 5–10 mm long, constricted at about the middle or above; seeds 1–2 in upper portion, several (5–8) in lower half. n = 12. NOTES: Mohave Desert in AZ, in washes, flats and slopes in rocky to sandy soils: La Paz, Mohave, (perhaps Yuma) cos. (Fig. 1C); 400–1400 m (1300–4600 ft); Mar–Apr; s CA, NV, and UT. REFERENCES: Windham, M.D. And G. Yatskievych. 2009. Vascular Plants of Arizona: Isoëtaceae. CANOTIA 5 (1): 27–29, 2009.