Xerophyte

Note

There is much variation within this species, the taxonomic position, habitats and ecology and populations size need further investigation, some of the “obvallatus” may correspond to other species.

Flowers

Flower buds are are held in the wool of the stem's apex, often with just the tips visible until early spring, when some sunny days come along and both the buds and plant start to grow. The plant will throw quite a few buds in and open several 3 cm flowers at a time over the course of a month. If the conditions are right it can bloom again later in the year. The blooms are quitw large, pale yellow or white, with purplish midstripes and reddish center; perianth-segments linear-oblong.

Spines

About 5-12, of which 3(-4) central spines subulate, ascending or spreading, the upper one flattened and wide, reddish brown, to 5 cm long, 3-4 mm wide, lateral 2 even wider, angular, spreading, and 4-6 radial spines shorter, white, perhaps not one-fourth the length of the longer ones (about 1 cm long).

Ribs

25 to 50, rather thin and undulate, very broad at the areoles.

Stem

Obovoid to globose, usually solitary but sometimes forming two stems, greyish or blue-green, depressed at apex reaching a height of 6-10 (or more) cm and width of 6-11(-15) cm.

Areoles

2-4 on each rib.