Flora of North America species comparison

± diffuse.

diffuse or short taproots, largest roots basally 19–63 (average 33)% of greater stem diam.

ovoid to cylindric (spheric), 4–16 × (2.2–)3–6(–6.5) cm;

tubercles (6–)8–11 × 3–6 mm, firm;

areolar glands absent;

parenchyma not mucilaginous;

druses in pith and cortex nearly microscopic, mostly spheric;

pith 1/8–1/4 of lesser stem diam.;

medullary vascular system absent.

deep-seated with only hemispheric apex protruding above ground level, spheric to cylindric, 1–2.7 × 0.6–1.7(–2.5) cm;

tubercles 2–5 × 2–4 mm;

areolar glands absent;

parenchyma not mucilaginous;

druses present in the stem and tubercle cortex (large lenticular druses absent);

pith 1/5–1/3 of lesser stem diam.;

medullary vascular system absent.

(17–)21–41 per areole, ashy white, gray, or pale tan, tips of largest spines pinkish tan to reddish brown or reddish black, all straight;

radial spines 15–41 per areole, gray, (5–)7–12(–13.5) mm, largest spines 0.1–0.2 mm diam.;

subcentral spines 0–6 per areole;

central spines usually 5;

outer central spines (1–)3(–7) per areole, erect or ascending;

inner central spines (0–)2 per areole, porrect or descending, longest spines (5–)10–15(–18) × 0.2–0.3(–0.5) mm.

15–28 per areole, appressed, lightly pigmented, pale tan to pinkish gray, weathering to gray, tips darker on some of largest spines, dark purplish brown to orange-brown, often partly overlain by an ephemeral whitish layer, peglike, not sharply needlelike, proximally compressed laterally;

radial spines 13–24 per areole, 3.5–5 × 0.1–0.5 mm, radial/central distinction obscure;

subcentral spines usually 1–4 in adaxial parts of areoles;

outer central spines (1–)3(–4) per areole, in bird’s-foot arrangement at adaxial parts of clusters in adults, straight, inner central spines 0 per areole, longest spines 4–6 × 0.3–0.6 mm.

apical or nearly so, (18–)20–30(–32) × 20–45(–4) mm, sterile distal part of flower tube 5–8.5(–11) mm, longer than stamen-bearing part;

outer tepals conspicuously fringed;

inner tepals 21 per flower, pure white, pale rose-pink, or pale lavender-pink, darker centrally, midstripes ± inconspicuous, (9–)11–19 × 1.5–2.5(–3.5) mm;

outer filaments cream;

anthers pale yellow or nearly white;

stigma lobes 4–6(–8), white, (1.8–)2–4 mm.

nearly apical, 13–16 × 15–27 mm;

outer tepals fringed;

inner tepals 15 or 16 per flower, pale rose-pink to magenta, shading gradually to paler pink or white basally, sometimes with a darker midstripes distally but lacking well-defined midstripes, proximally whitish to pale yellow-green, 7–12 × 2.5–4 mm;

outer filaments whitish to pale yellow-green;

anthers yellow to orange-yellow;

stigma lobes 4–8, green, 0.5–1.5 mm.

bright red [green to maroon], ellipsoid, cylindric, or narrowly obovoid, (8–)13–25 × 3.5–6.5(–7.5) mm, not very succulent;

floral remnant strongly persistent.

green (sometimes slightly yellow tinted), spheric, obovoid, or obconic, 1.5–6 × 1.5–4 mm, nearly dry;

floral remnant persistent but easily broken off.

reddish brown, darker with age, obliquely obovoid, 0.9–1 mm, pitted.

black, ± obovoid (to weakly pyriform), strophiole squarish, 0.8–1 mm, glossy, deeply pitted.

= 22 (as C. strobiliformis, C. varicolor, and Escobaria tuberculosa).

= 22.