Plants branched or unbranched; branches 0-several, not numerous, seldom rooting. Roots diffuse, upper portion not enlarged. Stems nearly spheric, 2.5-12 × 3.5-7 cm, firm; tubercles 9-10.5(-18) × 3-9 mm; axils appearing naked; cortex and pith not mucilaginous; latex absent. Spines ca. 9-16 per areole, brightly colored than M. grahamii, yellowish, pale pinkish tan, or brown (smaller spines paler), tipped dark chestnut brown to blackish, glabrous, sometimes ± pubescent when young; radial spines (8-)10-15 per areole, bristlelike, 6-10(-12) × 0.13-0.23 mm, stiff; central spines 1(-2) per areole, porrect, hooked, 11-20 × 0.2-0.4 mm; subcentral spines 0(-2) per areole, adaxial to central spines. Flowers (1-)2-3 × 1.2-2 cm; outermost tepal margins densely fringed, fringes 0.4 mm; inner tepals pinkish white with sharply defined magenta midstripes; stigma lobes bright red to red-purple, orange, or magenta, (3-)7-9 mm. Fruits bright orange-red, spheric to obovoid, 5-7 × 4-4.5 mm, level with or beneath spines, juicy only in fruit walls; floral remnant weakly persistent. Seeds black, 1-1.2 × 0.8-1 mm, pitted; testa hard; anticlinal cell walls straight; interstices conspicuously wider than pit diameters; pits bowl-shaped. 2n = 22.
|Counterclockwise fishhook cactus|