Flora of North America species comparison

± diffuse.

short, fleshy, enlarged taproots, basally ± 1/3–1/2 of 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, aerial parts inconspicuous, flat-topped to hemispheric (to ovoid or spheric in horticulture), almost completely withdrawing into substrate when desiccated, (2.4–)5–9 × 1.5–4.7 cm, above-ground portion 1–6.5(–9);

tubercles 5–9(–12) × 4–6(–7) mm;

areolar glands absent;

parenchyma not mucilaginous;

druses present, largest druses lenticular, 0.3–0.5 mm diam.;

pith 1/5–1/3 of lesser stem diam.;

medullary vascular system not recorded.

(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.

(12–)15–20(–25) per areole, white with brown tips (quickly weathering to gray) or the adaxial spines per areole dark gray-brown throughout; all radial spines or 1–3 adaxial spines sometimes interpreted as central, laterally compressed at base, 6–13 × (0.1–)0.2–0.3 mm;

subcentral spines 0(–3) per areole;

central spines 0(–3) per areole, appressed, straight, ± equal, 9.5–13(–15) × 0.2–0.3 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, 18–25 × 20–34 mm;

outer tepals fringed;

inner tepals 22–27 per flower, bright rose-pink or magenta, proximally paler, 10–17 × 2–4 mm;

outer filaments colorless or white to rose;

anthers orange-yellow;

stigma lobes (4–)5–6(–7), white, cream, or pale pink, 1–3 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, spheric or obovoid, (3.5–) 5–8(–10) × 3–6 mm, quickly drying;

floral remnant usually persistent.

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

dark brown, spheric, 0.9–1.1(–1.2) mm, pitted.

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

= 22.