Euphorbia Trigona Rubra
Euphorbia trigona 'rubra' is commonly known as African Milk Tree or Cathedral Cactus. It is native to central and west Africa. This plant can grow fairly tall (up to about 9 feet) and branch out to become bushy. This variation has beautiful, deep burgundy leaves. Give lots of sunlight to encourage blushing burgundy red color.
Chose either a single stalk in a 2.5" pot or three stalks in a 4" pot (shown in the photos). The younger stalks may not have long burgundy leaves yet.