The Eriosyce is very typical because the spines move considerably. In the dry season the spines are as close as possible to the body of the cactus (it is not possible to see any green of the body) while when it had some rain the spines open in such a way that it is possible to see the body and to count the ribs. This all happens in a timeframe of less than 2 weeks. The spines are probably also for frost protection because in winter time it get easely -20 degrees C (about 0 F)!
This icon appears next to images that have been 3rd party verified. Click Here to learn more. Click any picture below to enlarge.