For light requirements, crown of thorns plant needs bright light to full sun. It is easy to grow and drought-tolerant, and loves slightly dry, sandy soil. This succulent stores water in its stems just like cactus, so no need to water it everyday.
Found these two new babies yesterday. Based on my research, these are called Euphorbia milii, otherwise known as Crown of Thorns.
Euphorbia milii is a species of flowering plant in the spurge family. It originally came from Madagascar. It can grow up to 2 feet in height. For limited garden spaces like mine, pruning off the growing tips may control plants height.
transferred into green pots
How to propagate? Take 3 inches stem cuttings in spring or summer. Dip the cut ends in warm water for a few minutes to stop the flow of sap then allow to dry for 24 hours before inserting into barely moist potting mix. Cuttings will root in about 6 weeks.
Caution: Wear thick gloves when handling this plant because thorns are sharp and toxic. Its milky sap can irritate you skin, eyes, and mouth.
Source: Guide to House Plants