Quart plant Red Pencil Tree Euphorbia Sticks on Fire. This succulent shrub is a form of Euphorbia tirucalli, a plant that eventually can grow to 25 feet tall by 8 to 10 feet wide. Sticks on Fire lacks the chlorophyll of the parent plant and, as such, is much slower growing Native to Central Africa This thornless succulent thrives in full sun. Treat as you would any houseplant.