Flora of North America species comparison

erect, ovoid, becoming cylindric with age, 11–23(–40) × (4.5–)5.5–7(–10) cm;

ribs (13–)15–19(–21), crests rather sharply undulate;

areoles 5–11 mm apart.

erect, cylindric, 15–50 × 6–8 cm;

ribs 12–14(–16), crests slightly undulate;

areoles 15–25 mm apart.

19–28 per areole, straight, appressed (radial spines) or spreading in all directions (central spines), presenting relatively bristly appearance (except when spines very short, and then having relatively smooth appearance as in E. pectinatus), pink to pale yellow, white, or tan, less often dark brown or purplish, annual growth increments marked (often vaguely) by rings of spines with contrasting colors;

radial spines (16–)17–25(–28) per areole, 5–15(–25) mm;

central spines (2–)8–12(–15) per areole, terete, largest spines 4.5–9.5(–14) mm.

10–16 per areole, mostly straight or central spines strongly curving down near base;

radial spines 9–11 per areole, pale to golden yellow, aging darker colored or black, 12–15 mm;

central spines 1(–5) per areole, all yellow or whitish, terete, 20–25 mm.

7–8.5(–10) × 7–12 cm;

flower tube 10–20 × to 10 mm;

flower tube hairs 1–3 mm;

inner tepals either yellow (rarely orange-yellow, sometimes becoming salmon- or rose-pink with age), or rose-pink to magenta, proximal 5–30% green in either case, (25–)32–69(–77) × 8–23 mm, tips relatively thin and delicate;

anthers yellow;

nectar chamber 2–6 mm.

5–6 × 5–6 cm;

flower tube 15–20 × 15–25 mm;

flower tube hairs 2 mm;

inner tepals magenta to rose-pink, darker proximally, 30 × 5–12 mm, tips relatively thin and delicate;

anthers yellow;

nectar chamber 5–8 mm.

dark dull purplish to maroon (sometimes remaining green), 2–3.5 cm, pulp white to purplish pink.

green, sometimes tinged reddish to brownish, 20–30 mm, pulp white.

= 44.

= 22.