Seedtrees the Euphorbia tirucalli plant, also known as the Pencil Cactus, Fire Stick, or Indian Tree Spurge, is a succulent plant that is native to Africa. It is a fast-growing plant that can reach a height of 5 feet and a width of 6 feet. The plant has thick, cylindrical branches that are green in color. The leaves are small and fall off easily. The plant produces yellow flowers in the summer.