Greasewood is a perennial shrub native to semi-arid and desert areas in North America, particularly the western portion of the United States, southwestern Canada and Mexico. It is commonly called chicowood or black greasewood as well. In some areas, the shrub is considered to be an invasive weed because it can quickly cover large areas of land.
A unique looking shrub, greasewood typically grows upright to heights of three feet (.91 m) to seven feet (2.1 m). It has a whitish-gray colored bark, thorns, and fleshy leaves that it drops in the winter. It has both green colored female flowers and pinkish colored male flowers growing on a single plant. The flowers are situated upright along pipe-like spikes. The plant also has seeds that are shaped like small cups.
Saline or alkaline soils are ideal for greasewood shrubs. Interestingly, salts often accumulate under the shrub. Usually, the root systems of the shrubs run long and deep in search of water. There have been reports of roots reaching more than 50 feet (15.2 m) below the surface of the ground. It typically grows easily and is resistant to most disease.
Native American Indians have used the wood from greasewood for many tasks. For example, it has been used to create fuel for fires and to make tools. If a straight stem could be found, some groups used it to help them dig holes in the ground for their seeds. The seeds and leaves can be eaten in small amounts as well. They typically have a salty taste and are rich in vitamin A.
Livestock often eat greasewood leaves in small amounts. If the animals eat too much of the shrub and do not eat it in conjunction with other plant-life, it can cause severe illness or death. In large amounts, the leaves and young stems are quite toxic, especially for sheep. As the growing season progresses, the plant becomes even more toxic. Ranchers are often familiar with the symptoms of greasewood poisoning, such as unwillingness to move, weakness, drooling, unusual breathing patterns, and coma.
As long as the livestock has other food options, they will usually not overindulge in greasewood leaves. There are not any known treatments for greasewood poisoning, so prevention is the best option. Other small animals also consume the leaves, rarely experiencing any side effects. Some animals live under its branches or nest in the shrub itself, making it a valuable desert shrub.