in C. Backeberg and F. M. Knuth, Kaktus-ABC, 125. 1935.
Shrubs, decumbent to erect, essentially trunkless, 0.3–2.5 m. Stem segments green to purplish green, 6–30 × 1.5–2.5 cm; tubercles prominent, oval to elongate-elliptic, 0.7–3 cm, sometimes appearing as ribs; areoles elliptic, 4.5–5 × 3–3.5 mm; wool tan, aging dark gray. Spines (0–) 7–13 (–20) per areole, at most areoles, rarely obscuring stems, yellow to orangebrown with yellow tips, aging dark gray, subequal or 1–6 (–7) much longer to 3 cm; sheaths whitish or gold to brown, moderately loose. Glochids yellow-tan to redbrown in dense adaxial crescent and scattered, stouter ones at basal margins. Flowers: inner tepals yellow to greenish yellow; outer ones tipped red, 15–30 mm; filaments green or yellow; anthers yellow; style light green or cream-white (rarely pinkish) apically; stigma lobes cream-white to yellow. Fruits green to yellowish, drying gray-tan, short top-shaped to subspheric, 15–32 × 13–26 mm, leathery-dry, tuberculate, few-spined or spineless; proximal tubercles longest; umbilicus deep; rim slightly flanged; areoles 13–30. Seeds tan, squarish to angular in outline, warped, (4–) 5–7 × 4–5 mm, sides with 2–4 deep depressions; girdle smooth.
Varieties 4 (2 in the flora).
|1||Shrubs, suberect to decumbent; stem tubercles oval, shorter, usually 0.7-1.5 cm; spines/areole usually subequal||Cylindropuntia californica var. californ|
|1||Shrubs, suberect to erect; stem tubercles elliptic, longer, usually 1.5-3 cm; spines/areole commonly with 1(-3) central spines much longer||Cylindropuntia californica var. parkeri|