Pencil tree is a species of shrub that belongs to the Euphorbia genus and bears the scientific name Euphorbia tirucalli. Euphorbia tirucalli is typically found in tropical areas where there is very little rainfall. In the wild, this plant can be found in regions such as Africa and the Arabian Peninsula. The pencil tree has nondescript leaves, stems that look like pencil sticks, and is commonly called milkbush because of its milky sap. Euphorbia tirucalli can grow 20 to 30 feet (6 to 9 m) tall and can stretch from 6 to 10 feet (2 to 3 m) wide.
This plant has leaves that are not very noticeable because they are very small and cast off early. The flowers are also not easily seen because they are situated inside bracts, leaf-like structures that protect them. The young branches of this plant are green, while the trunk is brown and tree-like.
Stem cuttings are typically the method by which the pencil tree is propagated. The cuttings are usually dried to trap the milky sap inside. They are then inserted into a potting soil, which ranges from mildly acidic to mildly alkaline.
The pencil tree requires bright light for ideal growth. It can flourish with ordinary soil and some fertilization. Being highly drought tolerant, it only needs to be watered when it is very dry. It can tolerate a frost of about 25 ºF (-4 ºC), but only for a short time, as this plant is typically intolerant of freezing temperatures.
When in cultivation, the pencil tree is usually potted and put in places such as a patio. In tropical areas, it is often planted in a garden or yard for decoration. Another popular application of this plant is as a Christmas tree, in which case it is decorated with small Christmas lights. Some fishermen use juices from the mashed branches of the pencil tree to stun fish before attempting to catch them.
The branches of these plants need to be handled carefully due to their toxicity. Milky sap is present in all parts of the pencil tree, and any cut or damage to the plant can cause this sap to seep out. If the sap comes in contact with a person’s skin, it can cause it to become inflamed, itchy, and possibly develop blisters. This sap can also cause blindness for up to a few days if it comes in contact with a person’s eyes.