This was found, quite by chance, by Alfred Lau in 1972 while he was exploring the aptly named Sierra Obscura in the mountainous region of West Mexico on the border between Chihuahua and Sonora. He assumed it was a Graptopetalum and collected some specimens, which he seems to have taken back to his home in Mexico and forgotten.
It was not until nine months later, when the plants flowered in his greenhouse, that he realised he had made a stunning new discovery. He took the plant to Mexico City where it was shown to Dr Jorge Meyran who, together with Dr Moran from San Diego, originally published the plant in the Mexican Cactus and Succulent Journal. It was published as Tacitus bellus because of differences in the flower structure, although it is now considered to be a Graptopetalum.
In habitat it grows on steep cliffs and rock faces often with very little direct sun. In cultivation it will tolerate sun, but prefers shadier conditions. It is easy to grow in well-drained compost with a cool (but not freezing) rest over winter, to aid flower formation. A little water can be given occasionally in winter to avoid the leaves shrivelling too much.
The striking red flowers are born on inflorescences in spring and early summer. They are probably the largest in the Crassulaceae and will last for several weeks. Unfortunately the succulent rosettes appear to be an irresistible magnet for mealy bugs.
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