Xerophyte

Habit

It is a strongly spined cactus that branches vigorously from the base, forming large clumps or cushions. In habitat, the bodies are much compact and very spiny. When grown in pots, this species tends to elongate and have darker spines on most of the body, with grey-white spines only appearing on the oldest areoles at the bottom of the plant.

Central Spines

1(-4) thicker 3-6 cm long.

Seeds

Rounded-oblong 1,4-1,6 mm long, 1-1,2 broad and 0,8 mm thick, without papillae and surface sculpturing.

Roots

It has a shallow, diffuse root system or (less frequently) a short taproot.

Tubercles

With a rounded, raised edge and a wide base.

Flowers

At the apex, diurnal closing at night, fragrant, protracting the period of opening many days, campanulate, from the centre of the white wool at the apex. The outer segments of the perianth are linear red-brown or greenish. The inner segments are wide and yellow with a subtle red mid-stripe or occasionally pinkish.

Ribs

There are 10 to 20 strongly tuberculate especially in young specimens

Stem

Elongated-globose, pale to bright green or bluish green up to 40 cm tall, but usually less than 30 cm, and crowned by a dense mass of long white wool, particularly at flowering time.

Radial Spines

Few stout, 1-5 cm long, fairly slender or slightly curved, horizontal, pointing outwards, narrowed angle to the central spine, honey-amber, brownish-red or dark brown, becoming grey with age.

Areoles

Apical, convex, covered with short wool when young, later glabrous.