– Sulcorebutia rauschii (2013)
By Joe Merkelbach (July 2013)
The cactus chosen as the image for the 2013 HSCSS T-shirt is a South American native. It is a high-altitude specialist, found from about 8,000 to 12,000 feet in a mountain region of Bolivia in the vicinity of Sucre, one of the two capital cities.
Taxonomists have fairly recently placed this and allied species of Sulcorebutia back into Rebutia. There are dozens of synonyms for the species/subspecies. They do have differing traits from other rebutias that adapt them to rapidly drained substrates and high ultraviolet light intensity. Relatively large anchoring taproots hold them firmly in place in thin, rocky soils and allow the characteristic clumping of multiple heads.
One distinctive feature of the plant is its body color variability. Since it is alpine, it has increased exposure to high-energy ultraviolet light. The pink and grayish overtones, which naturally protect a bit better from these exposures, have been selectively bred by horticulturalists to arrive at vivid pink and bright, apple-green plant bodies.
The comb-shaped, dark-colored spines are arranged over very short, white felt in the areoles. The globular plant body has rows of flattened tubercles that can be recognized as a spiral pattern.
The flowers arise from the lower areoles of the globular plant bodies, but do not have tubes as long as typical rebutias and are a bright magenta in color. They make a spectacular display when a large clump is blooming simultaneously.
S. rauschii is a very attractive miniature that has CITIES II protection in habitat. Fortunately, it has taken fairly well to careful cultivation, so collectors who maintain it in proper rigorous conditions can grow showy specimens.