This squat dark green, nearly spineless cactus is found growing at over 6,600' (2000 m )in elevation. It's native habitat is the Sierra Madre Oriental Mountains of Mexico. It is found growing in semi-shady sights, at the base rocks and pines. The root is thick and tuberous. In the heat of summer this root can pull the plant down into the soil as protection.
http://www.viridis.net/cactus/mexico/img331-32-33.html
http://www.desert-tropicals.com/Plants/Cactaceae/Echinocereus_knippelian...
I have grown it for five years now with no winter damage. It is always the first Echioncereus cactus to bloom for me.