Euphorbia are mostly cactus like succulents with white sap that can irritate skin and even cause blindness. Use gloves when handling them and clean up sap with alcohol , not water.
Included in this group are crown of thorns, pencil cactus, Madagascar palm, and many that look like cacti. Many smaller euphorbia can be grown indoors and many are very rare and expensive. Others prefer outdoors and can grow very large. There are 1000 different types of euphorbia.