PLANT: Shrub 1–2 m tall, dense, intricately branched, thorny; branches often flexuous, yellowish, gray, or reddish to purplish black, glabrous or very sparsely puberulent; thorns slender and sharp. LEAVES: 1–5 cm long, 3–15 mm wide, glaucous green, glabrous, oblong-spatulate or oblanceolate to broadly elliptic; apex acute or rounded; base attenuate into a short petiole, the midvein and primary lateral veins usually visible. FLOWERS: pendulous, borne singly or in groups of 2–3 (Fig. 2G); pedicels slender, 4–16 mm long; calyx cup-shaped to campanulate, blue-glaucous, glabrous, 5–8 mm long, 5-lobed, the lobes lanceolate to ovate or elliptic, equalling or exceeding the tube in length, their margins sometimes sparsely pubescent; corollatube elongate-funnel form, 12–25 mm long, expanded conspicuously at the top, from white to lavender purple, most commonly greenish with purple veins, the 5 lobes oval or rhombic, 1/5 to 1/3 the length of the tube, their margins commonly remotely ciliolate; stamens exserted; filaments adnate to a little below the middle of the corolla-tube, the free base of the filaments and the adjacent corolla-tube pilose, or the filaments densely hairy nearly to top of corolla-tube; style varying in length from about equal to stamens to surpassing them. FRUITS: red or reddish blue due to glaucescence, ovoid, about 1 cm or slightly less in diameter, 4–50-seeded. n = 12. NOTES: Desert grassland, riparian areas, chaparral, pinyon-juniper woodland: all cos. except La Paz, Maricopa, Santa Cruz, Yuma (Fig. 1G); 800–2250 m (2500–7400 ft); Mar–Jun, occasionally at other times; CA to TX, n to UT and CO; Coah., N.L., S.L.P., Mex. REFERENCES: Windham, M.D. And G. Yatskievych. 2009. Vascular Plants of Arizona: Isoëtaceae. CANOTIA 5 (1): 27–29, 2009.