Snow urchin.... Well it looks like a snow-covered sea urchin I think. Actually it is a snow-covered prickly pear, Opuntia hybrid 'Nikolaj' in my winter hardy cactus garden. © Rob Huntley
A twig you say. Well I guess you could call it that but in fact it is a small treelike succulent caudiciform plant known as Pachycormus discolor. Mine is just a youngster with one "twig".
