Typically solitary but sometimes clustering, this cactus features stems ranging from globose to gently elongated. Its central spines are strikingly reddish-brown—erect, notably longer and sturdier than the radials. Up to 16 radial spines radiate outward, white with dusky tips, measuring 4–8 mm in length. When in bloom, the crown is encircled by a vivid ring of funnel-shaped flowers in deep purplish-red—a bold and beautiful display against its armored silhouette.

In the sun-drenched landscapes of northwestern Mexico, Mammillaria floresii thrives among a striking assembly of drought-adapted companions: towering organ pipe cacti (Stenocereus thurberi), the comb-like Pachycereus pecten-aboriginum, resilient prickly pears (Opuntia thurberi and O. lindheimeri), the cascading pink blooms of Antigonon leptopus, aromatic elephant trees (Bursera laxiflora), dwarf palms (Sabal mexicana), and the bold silhouettes of Agave vilmoriniana and A. bovicornuta.