Phytolacca dioica, commonly known as ombú, is the national tree of Argentina. This is a massive evergreen tree native to the pampas (lowlands) of South America, with an umbrella-like canopy that spreads to a girth of 12 to 15 meters and can attain a height of 12 to 18 meters. Its wood is soft and spongy, soft enough to be cut with a regular knife. The tree is covered with dark, glossy, green leaves. It has greenish-white flowers that grow in long clusters. These clusters droop from the weight of the crimson, ripe berries that develop from these flowers.
The ombu's massive, fire resistant trunks contain water storage tissue, making it an excellent choice for Israel's arid regions. The ombu is also known as the lighthouse of the pampas, since it provides shade for gauchos and other people that are traveling through the grasslands. Since the sap is poisonous, the ombu is not grazed by cattle and is immune to locusts and other pests. For similar reasons, the leaves are sometimes used as a laxative or purgant.
In Israel, the ombu is in demand for city parks, due to the shade they provide. For example, they were planted about twenty years ago in Moshav Sitriya. Ombus are good for planting next to benches, and children can climb its wide branches while their parents enjoy the tree's shade. The roots go down deep, so when planting, sewage pipes and underground electric cables must be taken into account. Since they are used to dry regions, they don't demand a great deal of water, although they are sensitive to cold.