Argyrodermas belong to the Ice Plant Family (Aizoaceae), and like most members of the family they are native to southern Africa. In particular, they favor quartz-fields in a dry area known as the Knersvlakte in western South Africa. Argyroderma delaetii is variable in flower color, but our pair pictured here have white flowers.
Aloe whitcombei is one of the few species in the genus native to Oman, in the eastern part of the Arabian Peninsula. It grows at the top of sheer cliffs overlooking the Indian Ocean, and can be hard to see without rappelling. Fortunately, it is not difficult to grow as a potted plant, and eventually it will reward you with short flower stalks which emerge from between the leaves and hook downward at the tip. At the bud stage, the flowers are pale yellow with striped green tips, but they turn white at maturity.
The genus Mammillaria is one of the largest groups in the Cactus Family (Cactaceae), with the majority native to Mexico. Often, their flowers come in a ring around the top of the stem, as can be seen here. Mammillaria hahniana is quite variable in its spines and wool, with some widely-grown forms having a much shaggier appearance than the plant pictured. It is native to east-central Mexico.
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