PLANT: Shrub 0.5–3 m tall, densely branched, rounded, thorny, glabrous or essentially so in ours; young branches flexuous, silvery-white to tan, the older branches with silvery-tan to dark brown bark. LEAVES: linear-terete, linear-spatulate, spatulate, or obovate, more or less succulent, 3–35 mm long, 1–8 mm wide, sessile or with a petiole 1–3 mm long; apex rounded to acute; base attenuate. FLOWERS: with pedicels 1–10 mm long, borne singly or in pairs in the leaf fascicles, white to pale purple (Fig. 2C); calyx cup-shaped, 1.5–3 mm long, 4–5-lobed or sometimes irregularly 2-tipped, the lobes triangular, about 1/4 the length of the calyx-tube, the margins sparsely ciliate; corolla 4–16 mm long, tubular or very narrowly funnelform, the lobes 4–5, ovate, 1.5–2 mm long, ciliolate, spreading; stamens hardly exserted to exserted 2–3 mm; filaments adnate to lower corolla-tube, their bases glabrous or sparsely hairy; style varying in length, from shorter than to as long as or longer than the stamens. FRUITS: red or orange-red, 3–9 mm long, ovoid or ellipsoid, many-seeded. N = 12. NOTES: Deserts, usually along washes: all cos. Except Apache and Greenlee (Fig. 1A); 250–1700 m (800–5600 ft); mainly Jan–Mar, but occasionally at other times; s CA, NV, UT, w NM; n Mex. A variable species of perhaps four varieties, three of which occur in AZ and intermix: L. a. var. wrightii with 4-lobed flowers 4–8 mm long, L. a. var. andersonii with 4–5-lobed flowers 8–16 mm long and leaves 3–16 mm long, and L. a. var. deserticola with 4–5-lobed flowers 8–16 mm long and leaves 20–35 mm long. REFERENCES: Windham, M.D. And G. Yatskievych. 2009. Vascular Plants of Arizona: Isoëtaceae. CANOTIA 5 (1): 27–29, 2009.