Xerophyte

Description

Usually solitary or slowly branching through basal shoots, but quite variable taxon with several forms.There are a number of varieties of this highly variable cactus species, but not all are universally recognized.

Flowers

Bell-shaped, 5 cm. long or less on lateral areoles, and the segments of the perianth are sulphur or lemon-yellow (but also white, orange or red), They have very hairy buds, The floral tubes have brown-white hairs /bristles and dark spine-tipped scales.

Spines

5 to 10 radial spines and 1 to 4 central spines, they are all more or less of the same length in a given plant (± 0,5 -3 cm.), but this species appears to be very variable regarding the length colour and number of spines in different populations. They are usually black or light brown at first, becoming grey or whitish-yellow as they age. The variety "brevispinum" has comparatively short and strong sharp spines.

Ribs

About 9-15.

Stem

Spherical, over time it becomes slightly cylindrical, growing to a height of 12 cm or more, and a diameter of 6 to 10 cm. The epidermis is green to dark blue grey, and become a clear powdery-grey in the older part of the stem (like some Copiapoa)

Areoles

At the apex of tubercles, at first are covered with yellowish-brown felt. The flower part of the areola is elongated, while the upper part curves around the sides of the rib, more or less in the shape of a small shield. As the tubercles widen in the course of growth, the areoles become elliptical and almost glabrous.