Flora of North America species comparison

depressed-ovoid to elongate-ovoid, 5–30 × 5–15 cm;

areoles oval, villous.

depressed-ovoid or occasionally elongate-cylindric, 5–15(–25) × 6–11.5 cm;

areoles circular to pyriform, villous to lanate.

smooth, hard and rigid, distinguishable as radial and central;

radial spines 10–30 per areole, spreading at right angles to tubercles, nearly straight, white to dull reddish brown, 8–20 mm;

central spines 6–12 per areole, widely spreading or nearly erect, reddish brown to nearly black, rigid, straight or slightly curved, base yellow or cream, 15–35 mm, less than 1 mm diam. at base.

distinguishable as radial and central: radial spines 11–15 per areole, white, 11–21 mm;

central spines 3–7 per areole, nearly porrect, brownish black aging to pale gray or white, straight or slightly curving at tips, 13–30 × 1 mm at base.

1–3.5 × 2.5–5 cm;

scales and outer tepals of flower tube minutely toothed, laciniate, or entire and undulate;

outer tepals with greenish brown midstripes, oblong-cuneate, 12–25 × 4.5–9 mm;

inner tepals white, pink, magenta, yellow, or yellow-green, 19–27 × 5–10 mm.

0.8–2.2 × 2–3 cm;

scales long fringed;

outer tepals brown with white margins, long fringed, 9–15 × 3–4.5 mm;

inner tepals yellow with purple veins, 15–20 × 4.5–6 mm.

green tinged with red, drying reddish brown, short cylindric, 6–11 × 5–10 mm.

greenish yellow, short cylindric, 12–15 × 6–9 mm.

gray to black, 2–3 × 1.5–2 mm, papillate but not rugose.

gray to nearly black, 3.5–5 × 3–3.5 mm, papillate and rugose.