Med. Fl. 2: 247. 1830.
Shrubs, forming clumps or often prostrate, usually only 1 or 2 stem segments tall, to 0.5 m (except in Florida where they may erect and reach to 2+ m with short trunk), flattened to obovoid, sometimes from tuberlike rootstocks. Stem segments not disarticulating, dark or bright shiny green, wrinkling when stressed, circular to broadly oblong to obovate, 5–17.5 × 4–12 cm, fleshy, usually tuberculate, glabrous; areoles 4–6 per diagonal row across midstem segment, oval to circular, 2–4 mm diam., not raised, sometimes somewhat sunken; wool tan to brown. Spines often absent or 1–2 (–3) per areole, spreading, whitish to brownish, terete, straight, and usually stout, 25–60 mm; occasionally also 1 deflexed spine present. Glochids in dense crescent of adaxial edge of areole and in dense tuft overtopping crescent in age, yellow to redbrown, to 4 mm. Flowers: inner tepals pale to bright-yellow throughout, 20–30 mm diam.; filaments yellow to orange; anthers pale-yellow to cream; style and stigma lobes white. Fruits greenish, tardily becoming apricot to brownish red, elongate, 30–50 × 12–20 mm, fleshy, tapering at base; pulp green and sour, becoming reddish and sweet under ideal conditions; areoles 10–18. Seeds tan, 3.5–4.5 mm diam., thickish; girdle protruding to 1 mm.
Ont., Ala., Ark., Conn., Del., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Mass., Md., Mich., Minn., Miss., Mo., N.C., N.J., N.Y., Nebr., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Va., W.Va., Wis.
Varieties 2 (2 in the flora).
"thickish" is not a number.