Flora of North America species comparison

diffuse or short taproots also present, largest roots basally less than 1/5 of stem diam.

cylindric, 5–27+ × 4.5–9 cm;

tubercles 10–14 × 6–10 mm, stiff;

areolar glands absent;

parenchyma not mucilaginous;

druses in pith and cortex relatively sparse, some giant, to 1 mm, lenticular;

pith 1/5–1/4 of lesser stem diam.;

medullary vascular system present (its vascular bundles numerous, small, and close together) or, in young plants, absent.

30–51 per areole, heavily or lightly pigmented, tan to purplish gray or white proximally, black or sepia distally, darkest when fresh, weathering to blackish, radial spines slightly contrasting with centrals, dull creamy white, dark tips present, usually purplish black;

radial spines 18–33 per areole, 12–18 × 0.15–0.45 mm;

subcentral spines 1–3 often present;

outer central spines 6–15 per areole, always radiating in adults protruding at all angles;

inner central spines 0–10 per areole (3–7 per areole on subadult plants), all porrect or nearly so, straight, largest spines 10–23 × 0.5–0.9 mm.

nearly apical, 20–30 × 25–39 mm;

outer tepals densely fringed;

inner tepals 21(–42) per flower, widely spreading, pale to intense rose-pink or rose-violet, with paler margins (white or pale rose), darker midstripes conspicuous, proximally white, 14–23 × 2–4 mm;

outer filaments white, pale rose, or pink with white bases, not greatly contrasting with inner tepals;

anthers bright dark yellow;

stigma lobes 5–9, widely spreading, pure white (rarely pale violet), 3–4 mm.

pale green throughout, narrowly fusiform-cylindric to narrowly obovoid, 16–25 × 6–12 mm, succulent;

floral remnant persistent Seeds reddish brown, obovoid to slightly comma-shaped, 1.3–1.6 mm, pitted.