Flora of North America species comparison

upper portion of primary root somewhat thickened and succulent proximally, otherwise fibrous.

fleshy taproots, to 24 cm, 5–8 cm diam.

flat-topped or spheric, 4–8 × 4–8 cm, ± flaccid;

tubercles 6–24 mm;

axils appearing naked;

cortex and pith mucilaginous;

latex absent.

cylindric to ovoid-cylindric, commonly 5–15(–25) × 3.5–7(–10) cm, flaccid;

tubercles 4 mm diam.;

axils short woolly;

cortex and pith mucilaginous;

latex absent.

9–31(–34) per areole, white, usually tipped brown;

radial spines 8–30 per areole, in 1 series, glabrous (puberulent in first year flowering plants);

lateral spines bristlelike, 7–11 mm, stiff, longest and thickest of spines;

adaxial spines often darker;

central spines 1–4(–7) per areole, porrect or strongly projecting, 1 or all hooked, (5–)12–14(–21) mm;

subcentral spines 0.

21–64 per areole, dark or light colored, depending largely on substrate color, glabrous (to hoary);

radial spines 30–46(–60) per areole, white, bristlelike, 6–10 × 0.09–0.15 mm, stiff;

central spines 1–3(–4) per areole, porrect or strongly projecting, usually hooked, (6–)13–18(–25) × (0.2–)0.3(–0.4) mm;

subcentral spines several, often 12+ per areole, radiating in all directions, often resembling supplementary ring of radial spines, barely distinguishable from radial spines, stouter, longer and dark tipped or purplish.

2.5–3.5(–5.2) × 2.2–4.5(–7.5) cm;

outer tepal margins conspicuously fringed;

inner tepals rose-pink or magenta [white], margins often paler;

stigma lobes yellow or pale green (rarely reddish).

2.5 × 2.5–3.5 cm;

outermost tepal margins long fringed;

inner tepals pink to rose-purple, margins sometimes paler or white, at least proximally, 24–26 × 4 mm;

stigma lobes yellow-green to green.

green or dull purple, spheric to ovoid or obovoid, (9–)13–20(–28) × (6–)7–1.9(–26) mm, juicy throughout;

floral remnant persistent.

bright red, ellipsoid or cylindric to clavate, (8–)15–30 × 5–10 mm, juicy only in fruit walls;

floral remnant quickly deciduous, leaving conspicuous abscission scar.

black, 1.3–1.5 mm, pitted;

testa hard, anticlinal cell walls straight (not undulate);

interstices conspicuously narrower than pit diameters;

pits bowl-shaped.

black, conspicuously strophiolate, 1.4–2.4 × 1.4 mm, pitted and rugose;

testa hard;

anticlinal cell walls straight (not undulate);

interstices narrower than pit diameters;

pits bowl-shaped;

strophiole tan, large, corky.

= 22.

= 22.