Xerophyte

Petals

lanceolate to narrowly lanceolated, up to 4 mm wide and 21 mm long, inside and outside sulphur-yellow, shining. Stylus

Central Spines

4 – 8 (of which 4 true centrals and 3-4 intermediate), up to5 mm long, Longer and stouter, spreading, copper-red or brown. The central spines often are not present in the new apical growth but appears later.

Seeds

Helmet-shaped, black. Length 0.65 mm, width 0.5 mm, height of 0.4 mm, Hilum oval, curved, light brown. Testa convex to hemispherical, bordered with 5 to 7 adjoining cells, 0.03 - 0.07 mm Ø. Microphylar hole 0.13-0.1 mm Ø and 0.04 mm.

Description

It is a small and very beautiful cactus completely covered with wool and spines. Branches to form small groups or rarely remain solitary,

Flowers

Opening at the top of the stem, approx 35 mm long and 40 mm wide, sulphur-yellow, odourless, self sterile.

Spines

Very dense white and copper coloured, not stinging. The spines in the blooming areoles are often darker.

Ribs

21 to 27, approx 5 -7 mm wide and 2-4 mm highly, arranged into tubercles, on which the areoles sits.

Stem

Cylindrical, 3,5-7 cm in diameter, 6-10(-15) cm tall, epidermis dark green concealed by the dense spines.

Radial Spines

40 - 50 up to 7 mm long, very fine, pure white, lying close, radiating, interlacing with the spines of the adjacent areoles.

Fruits

Small 6-7 mm broad and long, fleshy, pinkish, cover with white cotton wool, drying yellowish, irregularly opening with the releasing of part of the seeds to the ground (but some of the seeds remain on the plant). Each fruit contains approx 80 seeds.

Areoles

Roundish, 2-3 mm in diameter, very close one to each other (approx 2 mm apart), filled by white wool that persist for some years, then naked. Annual increase 5-6 areoles per ribs.