Found in Ethiopia, Kenya, Somalia, Tanzania & Uganda, Caralluma schweinfurthii is another sprawling Stapeliad. It is very similar to C. hesperidum in having beatifully marked stems. But it's flower is smaller, yellow and spotted with red.
     I got a whole potfull of this at Home Depot marked Caralluma pyaranthoides. Most of it rotted but I managed to root some cuttings. It has never flowered but Sue Welborn, a fellow member of the Davesgarden.com gardening forums, has allowed me to use the pictures below. Thanks Sue :-)

Flower in late August

A closer view