Flora of North America species comparison

some-what lax often sprawling, longest stems sometimes prostrate, cylindric, 8–40(–100?) × 3.2–15 cm;

ribs (6–)7–10(–12), crests essentially uninterrupted;

areoles (11–)14–52 mm apart.

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.

6–14 per areole, straight or central spines slightly curved throughout their lengths, ± opaque, white, pale tan, or purplish gray, often extensively tipped or banded with brown;

radial spines 5–10(–13) per areole, 9.5–40(–47) mm, usually less than 1/2 as long as central spines;

central spines 1–4(–5) per areole, all or mostly projecting, abaxial spine porrect or descending, frequently compressed or angular in cross section (sometimes sulcate, keeled, or striate), (12–)20–84(–96) mm.

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.

(4.5–)5–7.5 × 5–5.6(–9) cm;

flower tube 10–30 × 10–22(–40) mm;

flower tube hairs 1–2 mm;

inner tepals pink or magenta, darkest proximally, 28–55 × 8–14(–20) mm, tips relatively thin and delicate;

anthers yellow;

nectar chamber 4–6 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.

pale yellow-green or dull reddish, 20–30 mm, pulp white or pale pink.

green, 15–25 mm, pulp white.

= 22.

= 22.