Flora of North America species comparison

± diffuse.

± diffuse, less than 1/4 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.

usually more than 1/2 above ground (sometimes deep-seated and flat-topped in winter, in cold climates and/or in immaturity), oblate, spheric, ovoid, obovoid, or cylindric with age, 2.5–20 × 3–11 cm;

tubercles 8–25 × 3–8 mm, stiff or ± flaccid;

areolar glands absent;

parenchyma not mucilaginous (except possibly in far north);

druses in pith and cortex present, some large, 0.7–1 mm diam., lenticular, usually conspicuous in old parts of stem;

pith 1/5–2/3 of lesser stem diam.;

medullary vascular system present.

(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.

11–55 per areole;

radial spines 10–40 per areole, weakly appressed or tightly appressed, pectinately arranged in subadults of some populations, either bright white, ashy white, pale tan, pale pinkish gray, or reddish brown (rarely stramineous), tips dark bright pinkish brown, reddish brown, dark brown, orange-brown, or pinkish orange on all or only largest spines (dark tips rarely absent), 7–22 × 0.08–0.6 mm;

subcentral spines sometimes present in adaxial parts of clusters;

central spines straight, snowy white, ashy white, reddish brown, sepia, purplish gray, pinkish gray, brownish red, pinkish brown, horn colored, pale tan, dark purplish brown, or stramineous, opaque or vitreous, fading, then blackening with age;

outer central spines 3–14 per areole;

inner central spines (0–)1(–4) per areole, appressed or strongly projecting, in “bird’s-foot” arrangement or radiating like spokes, longest spines 9–25 × 0.2–0.7 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.

slightly subapical, 20–57 × 25–67(–90?) mm;

outer tepals conspicuously fringed;

inner tepals 21–56 per flower, usually spreading, recurved, pale rose-pink to reddish pink or magenta, sometimes with darker midstripes, sometimes shading to white or pale greenish, proximally magenta, often darkest distally, 15–35 × 1.3–6 mm;

outer filaments magenta or basally white (rarely entirely white or greenish white), seldom contrasting with inner tepals and, if so, then paler;

anthers bright dark yellow (rarely orange-yellow);

stigma lobes 5–13, erect or ascending, white to magenta, 2.5–5.5 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, exposed portions slowly turning dull brownish red, ovoid to obovoid, 12–28 × 7–20 mm, juicy;

floral remnant persistent.

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

bright reddish brown, comma-shaped or nearly obovoid, (1–)1.3–2.4(–3) mm, pitted.

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

= 22.