Aged specimens of this species form rather rumpled-looking old barrel cacti of impressive stature to 1 m across and twice that in height.  Seedlings are taut-skinned, glaucous-bodied, tuberculate gems. Their slow growth (our seed was sown Aug. 28, 2002, producing seedlings now about 4 cm in diameter) gradually results in a greener barrel cactus -- often with purple banding during adolescence – that eventually becomes a fine landscape specimen in suitable climates (it can withstand frost to 20° F or lower).  Plants from seed of HBG 21572,  E.F. Anderson 1694, collected Jan. 16, 1961, ca. 1 mile SW of Rayones, Nuevo León, Mexico.  $6.