Ferocactus glaucescens

Ferocactus glaucescens, the glaucous barrel cactus, is a species of flowering plant in the family Cactaceae, native to the limestone hills of Hidalgo, endemic to México. It is a spherical or cylindrical cactus growing to in diameter, with long yellow spines and yellow flowers in summer.
In cultivation in temperate regions it must be grown under glass. It has gained the Royal Horticultural Society's Award of Garden Merit.
There is a spineless form, "Ferocactus glaucescens "forma" nuda" (inermis).