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.

usually erect, cylindric, 10–40 × 5–10 cm;

ribs 8–13, slightly 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–]9–18 per areole, straight or contorted;

radial spines 7–14 per areole, appressed, yellowish to brownish, becoming gray, 5–25 mm;

central spines 1–4 (c Arizona and Mexico) or 3–8 (elsewhere) per areole, spreading to projecting outward, brownish yellow to reddish black, becoming gray, terete (c Arizona) or angled to terete (elsewhere), 15–50 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.

5.5–7 × 3.5–5 cm;

flower tube 25–35 mm;

flower tube spines 5–15 mm, hairs to 2 mm;

inner tepals bright orange-red to dark red distally, proximally paler (bases sometimes yellow or whitish), 25–40 × (5–)10–15 mm, tips thick and rigid;

anthers pink to brick red or purple;

nectar chamber 6–10 mm.

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

green, brownish tinged, 20–30 mm, pulp white.

= 22.

= 22.