Flora of North America species comparison

appearing as taproots at soil surface, branching, and ultimately diffuse.

depressed-ovoid to elongate-ovoid, 5–30 × 5–15 cm;

areoles oval, villous.

unsegmented, green or gray-green, obconic-cylindric to spheric or depressed-spheric, 2–15 × 1–15 cm;

tubercles distinct, not confluent into ribs, pyramidal, conic, truncate-conic, cylindroid, or mammillate, 2–10 mm;

areoles circular, oval, pyriform, or elliptic, spiny and short or long woolly or glabrate;

areolar glands absent;

cortex and pith usually mucilaginous.

smooth, hard and rigid, distinguishable as radial and central;

radial spines 10–30 per areole, spreading at right angles to tubercles, nearly straight, white to dull reddish brown, 8–20 mm;

central spines 6–12 per areole, widely spreading or nearly erect, reddish brown to nearly black, rigid, straight or slightly curved, base yellow or cream, 15–35 mm, less than 1 mm diam. at base.

3–45, reddish tan, pink, gray, or white, needle-shaped or awl-shaped to hairlike, 6–30 × 0.3–1 mm, smooth and hard, less often corky or spongy and soft, finely puberulent to glabrous;

radial spines 3–35 per areole, spreading, erect, recurved, or somewhat pectinate, straight or irregularly curved, 1–32 mm;

central spines 0–12, straight or curved upward, needlelike, hairlike, or corky, terete to flat.

1–3.5 × 2.5–5 cm;

scales and outer tepals of flower tube minutely toothed, laciniate, or entire and undulate;

outer tepals with greenish brown midstripes, oblong-cuneate, 12–25 × 4.5–9 mm;

inner tepals white, pink, magenta, yellow, or yellow-green, 19–27 × 5–10 mm.

diurnal, borne at adaxial margins of areoles at stem apex, funnelform, 1–4 × 1–2.5 cm;

outer tepals greenish or purple midstripes, pink or yellow margins, 9–25 × 3–9 mm, margins fringed, denticulate, or entire;

inner tepals yellow, peach, pink, magenta, cream, or white, 4–15 × 3–7 mm, margins entire to fimbriate;

ovary smooth, scaleless to few scaled, spineless;

stigma lobes 5–9, yellow to green, 0.7–1.5 mm.

green tinged with red, drying reddish brown, short cylindric, 6–11 × 5–10 mm.

dehiscent along 1 vertical suture, green or greenish yellow, often turning reddish brown, thin walled, cylindric, spheric or turbinate, 4–15 × 3–11 mm, becoming dry at maturity, smooth, scaleless or with few broad, thin scales;

pulp greenish to white, scant;

floral remnant deciduous.

gray to black, 2–3 × 1.5–2 mm, papillate but not rugose.

brown, black or gray, irregularly or obliquely obovoid or pyriform, 1.5–5 × 1–3.5 × 1–1.5 mm, papillate, sometimes also rugose, shiny;

testa cells convex.

= 11.