Flora of North America species comparison

mostly erect, cylindric, (5–)10–40 × 4.5–8 cm;

ribs 10–15, crests slightly undulate;

areoles 10–15 mm apart.

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.

8–16 per areole, usually straight, individual spines with broad zones of different colors: yellowish, reddish brown, or gray to black, or white to black, becoming gray;

radial spines 7–15 per areole, 5–15 mm;

central spines 1–3 per areole, divergent-porrect, 15–75 mm, all terete.

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.

6–10 × 8–10 cm;

flower tube 10–20 × 15–40 mm;

flower tube hairs 2.3–4 mm;

inner tepals rose-pink to magenta [rarely nearly white], with midstripes darker, darker magenta or sometimes purplish maroon near base, (20–)35–52 × 12–20 mm, tips relatively thin and delicate;

anthers yellow;

nectar chamber 3.3–5 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.

bright red or orange-red, 20–30 mm, pulp white or sometimes pink.

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

= 44.

= 22.