Euphorbia ammak, commonly known as Ammak or Desert Cactus, is a striking succulent plant native to the arid regions of Saudi Arabia, Yemen, and Somalia. Despite its common name, it is not a true cactus but belongs to the Euphorbiaceae family.

The Euphorbia ammak features a tall, columnar growth habit, similar to the shape of a Menorah, which can reach impressive heights of up to 20 feet (6 meters) in its natural habitat. The stems are ribbed and covered with prominent spines or thorns. The plant's color ranges from green to yellow, with the older stems often developing a textured, rough bark.

Clusters of small leaves form along the margins of the Ammak with flowers budding in the Spring/Summer time.

Euphorbia ammak is known for its adaptability to arid conditions and its ability to store water in its thick stems, enabling it to survive in dry environments. However, it is important to handle this plant with care as it produces a milky sap that can cause skin irritation and is toxic if ingested.