Flora of North America species comparison

diffuse or short taproots also present, largest roots basally less than 1/5 of stem diam.

± succulent in largest, often massive and difficult to excavate.

cylindric, 5–27+ × 4.5–9 cm;

tubercles 10–14 × 6–10 mm, stiff;

areolar glands absent;

parenchyma not mucilaginous;

druses in pith and cortex relatively sparse, some giant, to 1 mm, lenticular;

pith 1/5–1/4 of lesser stem diam.;

medullary vascular system present (its vascular bundles numerous, small, and close together) or, in young plants, absent.

deep-seated, aerial portion conspicuous, hemispheric to short cylindric, shape sometimes obscured by profusion of immature branches, 5–23 × (1.5–)4–8(–13.5) cm;

tubercles unusually large, conspicuous, (10–)15–38(–45) × 6–15 mm, ± flaccid or flabby;

areolar glands seasonally conspicuous;

areolar grooves short, extending 1/2–3/4 distance from spines toward tubercle axils;

parenchyma mucilaginous;

pith narrow, ca. 1/10 of lesser stem diam.;

medullary vascular system absent.

30–51 per areole, heavily or lightly pigmented, tan to purplish gray or white proximally, black or sepia distally, darkest when fresh, weathering to blackish, radial spines slightly contrasting with centrals, dull creamy white, dark tips present, usually purplish black;

radial spines 18–33 per areole, 12–18 × 0.15–0.45 mm;

subcentral spines 1–3 often present;

outer central spines 6–15 per areole, always radiating in adults protruding at all angles;

inner central spines 0–10 per areole (3–7 per areole on subadult plants), all porrect or nearly so, straight, largest spines 10–23 × 0.5–0.9 mm.

7–21[–55] per areole;

radial spines (3–)9–15(–18) per areole, white, gray, tan, or brown, (9–)16–25(–50) mm;

subcentral spines 2–3 in adaxial part of areole;

central spines (1–)3–8 per areole, (tan to) pale gray to black, abaxial central spine porrect or descending, others weakly appressed or ± projecting spines, slightly curved, usually angular in cross section (terete), sometimes flat and grooved on 1 side and rounded on the other, often slightly flexible, (15–)25–35(–55) mm, all equal or abaxial spine longest.

nearly apical, 20–30 × 25–39 mm;

outer tepals densely fringed;

inner tepals 21(–42) per flower, widely spreading, pale to intense rose-pink or rose-violet, with paler margins (white or pale rose), darker midstripes conspicuous, proximally white, 14–23 × 2–4 mm;

outer filaments white, pale rose, or pink with white bases, not greatly contrasting with inner tepals;

anthers bright dark yellow;

stigma lobes 5–9, widely spreading, pure white (rarely pale violet), 3–4 mm.

apical or nearly so, 30–50(–60) × (30–)40–70 mm;

outer tepals heavily fringed;

inner tepals 20–25 per flower, bright rose-pink or magenta, often with darker midstripes and paler margins, 30–40 × 4.5–6 mm;

outer filaments greenish white throughout or distally purplish pink;

anthers bright yellow;

stigma lobes 6–13, white or pale yellow, 3–6 mm.

pale green throughout, narrowly fusiform-cylindric to narrowly obovoid, 16–25 × 6–12 mm, succulent;

floral remnant persistent Seeds reddish brown, obovoid to slightly comma-shaped, 1.3–1.6 mm, pitted.

dark green, ovoid to obpyriform or ellipsoid, (10–)13–25(–30) × 12–18 mm;

floral remnant strongly persistent.

reddish brown, ± comma-shaped to spheric, 1.2–1.5 mm, finely and weakly raised-reticulate.

= 22.