16. Cylindropuntia abyssi (Hester) Backeberg, Cactaceae. 1: 184. 1958.
Peach Springs cholla
Opuntia abyssi Hester, Cact. Succ. J. (Los Angeles) 15: 193, fig. 94 (upper left, bottom). 1943
Trees and shrubs, openly branched, to 1 m. Stem segments somewhat detachable, 8-14 × 1.8-2.5 cm; tubercles prominent, 0.6-1.5 cm, moderately broad; areoles elliptic, 5-7 × 2.5-3.5 mm; wool white to gray. Spines in brushlike clusters of 10-15 per areole, flexible, whitish to yellowish tan, aging gray; abaxial ones erect to descending, recurved, angularly flattened to flattened, sometimes twisted, the longest 23-38 mm; adaxial ones ascending, erect, divergent, terete to angularly flattened basally, the longest 18-32 mm; sheaths silvery white. Glochids in inconspicuous small adaxial tuft, pale yellow, 0.5-1.5 mm, few much longer and scattered along periphery of areole. Flowers: inner tepals pale yellow to greenish yellow, spatulate, 15-20 mm, apiculate; filaments yellow; anthers yellow; style off-white; stigma lobes yellowish. Fruits green becoming dull yellow, dry, tuberculate, spineless or with 1-2 short spines; tubercles subequal in length; umbilicus deep, 7 × 15-18 mm; areoles 16-24. Seeds tan, slightly angular and warped, 3-4 × 3.2-3.5 mm; girdle smooth. 2n = 22.
Flowering spring-early summer (Mar-Jun). Desert scrub, limestone ledges and crests; 500-800 m; Ariz.
Cylindropuntia abyssi is tentatively viewed as a narrow endemic relict in Peach Springs Canyon, Mojave County, Arizona, but may well be a persistent hybrid derivative, most likely involving C. bigelovii.
Hybrids between Cylindropuntia abyssi and C. acanthocarpa have a shrub habit, long-divergent and loosely sheathed spines, and more elongate tubercles than C. abyssi.