Xerophyte

Habit

It is a large sized often elongated and columnar plant slowly branching from the base, forming large, open clumps with (usually) few individual stems.

Central Spines

0-1(-2) similar in colouration.

Seeds

Black and shining.

Flowers

Yellow funnelform, 1,5 to 2,5 cm in diameter. The Ovary is naked; it needs a lot of sunlight to bloom, so it's pretty rare to have blossoms when in cultivation in greenhouses.

Ribs

14-22(-37), rounded, broad, obtuse, wavy, almost straight, thickened at areoles (tuberculate), becoming flattened. The ribs in the younger specimen have very geometric and conspicuous tubercles, typically with a hexagonal base.

Stem

Globose to cylindrical, up to 1 m high, 20-30 cm across, pale olive-green, grey-green or ash-grey to silvery-blue when old, the apex is very spiny, covered with reddish, orangish or yellowish-brown wool. The whitish-grey coloration is a waxy coating presumably to prevent desiccation in it's extremely dry environment. In cultivation the white waxy bloom is often not produced, revealing a brownish epidermis.

Radial Spines

Up to 7, about 1-2 (or more) cm long, hard, horny-yellow to brown coloured, later brown-black, terete, tipped darker, spreading, straight or slightly curved.

Fruits

1,5 to 2 cm long.

Areoles

Up to 18 mm in diameter, orangish, fading in grey as they become older.