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.

weak, sprawling, soon decumbent [erect and rhizomatous], ± 10–60 × 1–2[–6] cm;

ribs 4–5, crests sharp and straight to poorly defined and undulate;

areoles 5–12 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.

(3–)4–7(–9) per areole, usually very stiff and straight, yellowish, tan, ashy white to dark gray, or pale pink, tips dark, all terete;

radial spines (3–)4–6(–8) per areole, spreading, 6–37 mm;

central spines 0–1 per areole, porrect or ascending, 4–36(–60) 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.

6–10 × 7.5–10(–15) cm;

flower tube 20–25 × 8–20 mm;

flower tube hairs 3–6 mm;

inner tepals brilliant pink or magenta distally with distinct white or yellow proximal regions of variable extent [very rarely white throughout], 3.5–6 × 9–18 mm, tips relatively thin and delicate;

anthers orange-yellow;

nectar chamber 3–6 mm.

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

green, (10–)15–25 mm, pulp white.

= 22.

= 22.