Flora of North America species comparison

mostly nearly erect when young, frequently decumbent in old age, cylindric, 4–15 × 2–3(–7) cm;

ribs (6–)7–10, crests strongly undulate;

areoles 10–15 mm apart.

8–12 per areole, straight, appressed-spreading (radial spines) or projecting to appressed (central spines), white, yellow, or brown and white;

radial spines 7–10 per areole, to 15 mm;

central spines 1(–4) per areole, brown, terete, to 25 mm.

funnelform, 7–9 × 7–12 cm;

flower tube 20–30 × 10–30 mm;

flower tube hairs 1 mm;

inner tepals yellow, proximally orange-red to purple, 15–40 × 10–20 mm, tips relatively thin and delicate;

filaments yellowish to orange-red;

anthers yellow;

nectar chamber 4–6 mm.

green, 15–25 mm, pulp white.

= 22.