Ferocactus cylindraceus subsp. cylindraceus

Stems straight, erect or nearly so (or leaning), cylindric, (20-)45-150(-300) × (20-)25-40(-50) cm; ribs (18-)21-31, shallowly notched immediately above each areole. Spines 12-32 per areole, central spines and larger radial spines whitish, yellow, pink, dull red, or brown; smallest spines per areole slender, sometimes bristlelike, less than 1 mm diam. (rarely absent); central spines 4 per areole, major rigid central spines surrounded by weaker subcentral spines; principal central spine moderately curved, sometimes twisted, usually not strongly hooked except on relatively young plants, annulate, adaxial surface usually flat or even concave, 36-140[-170] × 2-4.5 mm. Flowers maroon outside, yellow inside, 3-6 × 4-6 cm; inner tepals commonly yellow, (rarely with reddish midstripes, very rarely orange to red with a darker red midstripes); stigma lobes yellow (to red). Fruits ± readily dehiscent through basal pore, bright yellow (very rarely reddish), 30-40(-50) × 15-20 mm, leathery or fleshy, locule dry, hollow except for seeds. Seeds (1.5-)2-3 mm, pitted. 2n = 22.