Thelocactus leucacanthus grows in clusters or forms large multi-headed cushions up to wide. The yellowish-green, globular to short cylindrical plants reach in height and in diameter. The plant has 7 to 14 tuberous ribs running vertically or spirally, with conical cusps up to high, wide, and long. The
areoles, up to long and wide, have extrafloral nectaries. Occasionally, a single central spine, yellowish-white to nearly black, grows up to long, with 6 to 20 radial spines that are long and straight or slightly curved. The yellow, purple, or crimson flowers reach up to long and in diameter. The green to yellowish fruits grow up to long and wide, drying and cracking at the base when ripe. They contain seeds up to long and wide, with polygonal or square testa cells. File:Thelocactus leucacanthus.jpg|Plant with bloom File:Thelocactus leucacanthus var. schmollii (6089241104).jpg|Purple flower form ==Distribution==