Xerophyte

Description

Body usually solitary, globose. Hardly offsetting in cultivation.

Phenology

Blossoming time

Roots

Carrot-shaped

Juvenile Spines

Plumose, soft, flexible, not pungent. During the first year near the base thin feathery hairs begin to form. Often the spine is densely covered, with hairs up to its tip. Spines of two-year-old seedlings (see figure) differ only in being longer and more ragged. There are no central spines; all are radial.

Spines

Close-packed, radial, mostly 12, awl-shaped, very sharp, sticking out up to 17 mm, snow-white, translucent, young almost glass-like, black tipped. Central spines 1, much longer (up to 30 mm), somewhat stronger, white, but at the top and further down, dark brown to black. Later they become grey, and the radial spines radiates horizontally, almost comb-like.

Stem

Spherical or somewhat conical, rounded above; apex rather deeply sunken, but fully hidden by the snow-white, dense wool; blue-green, 6-8 (10) cm high and 6-8 cm in diameter. Ribs fully arranged in tubercles, from 13 to 21, rather dense spirals, rhombic or sub-quadrangular, conical; the top somewhat compressed from the sides, with sharp upper and lower edges. The seedlings tend to become quite cylindrical.

Fruits

Fruits, urn-shaped, are 12 mm long.