Flora of North America species comparison

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

diffuse, upper portion not enlarged.

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.

nearly spheric to more often cylindric or long cylindric, 5–30 × 5–7 cm, firm;

tubercles 5–12 × 3–7 mm;

axils woolly, bearing 4–15 bristles (0 in young growth) as long as tubercles;

cortex and pith not mucilaginous;

latex absent.

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.

14–26 per areole, pinkish or reddish brown to black, glabrous;

radial spines 11–22 per areole, usually white, bristlelike, 5–7 mm, stiff;

central spines (1–)3–4 per areole, abaxial 1 porrect, hooked, longer, stouter, adaxial central spines ascending with radial spines;

subcentral spines 0.

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.

10–22 mm;

outermost tepals entire or short fringed;

inner tepals cream, usually with pinkish or reddish midstripes, longer in bisexual flowers, 5.4 mm diam.;

stigma lobes yellow to greenish yellow or brownish green, 8 mm.

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.

bright scarlet, clavate or ovoid, 10–25(–35) × 10 mm, juicy only in fruit walls;

floral remnant persistent.

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.

black, 0.8 × 0.6 mm, pitted;

testa hard;

anticlinal cell walls straight (not undulate);

interstices conspicuously wider than pit diameters;

pits bowl-shaped.

= 22.

= 66.