Fockea is a genus of 10 species of semi-decidous caudicifrom vines found in Southern Africa. Fockea edulis is probably the most common in cultivation and is grown for its bumpy white caudex. The caudex slowly grows up to 2 feet in diameter and the branching vine several feet tall. For centuries the Hottentot tribe have used the tubers for food. Though poisonous raw, it is edible cooked, in fact the name edulis means "edible". The plant produces clusters of tiny green flowers in late summer. They appreciate a fair amount of water while growing but should be watered only occasionally in winter.
     I got this one from Shoal Creek Succulents last fall and it stayed mostly leafed out through the winter in my greenhouse. Now in July it's happily growing under my Mulberry tree in the back yard. I love the shape of this ones caudex. Below is a closer view.