Euphorbia resinifera dwarf cactus
(This plant comes in a 3.5" pot. You will receive a very similar plant to the one in the picture. It may or may not be blooming at the time of your purchase. The plant is shipped in its pot to prevent any damage to the roots).
This is a dwarf form of the euphorbia resinifera, some of the easiest and care-free Euphorbias to grow, both in pots and in the ground in areas with a mild climate, but they can even be grown indoors. They grow well in a very draining mineral potting substrate, but they aren't picky about soil. During the summer they enjoy average feeding and watering. When dormant, plants are relatively cold tolerant. They will rapidly mound, branch and spread. These are widely adaptable, able to take full sun that helps the plants to keep their compact growth-form.
Some of the information in this description has been found at desert-tropicals.com, llifle.com and cactus-art.biz