Several shrubs are commonly called greasewood, especially the creosote bush (genus Larrea). Sarcobatus vermiculatus, a member of the Goosefoot Family, is the “true” greasewood, true greasewood being one if its common names, along with black greasewood.
A native, perennial shrub, greasewood grows in sunny, flat areas around the margins of playas (saline, alkaline flood plains), in dry stream beds and arroyos. This halophyte (saline or alkaline loving) grows from 4,000 to 7,100 feet in the western United States, Alberta and Saskatchewan. It can reach more than 7 feet in height.
The spiny stems are white to grey. Greasewood stems splinter when broken, causing injury to animal digestive systems if eaten. Flat tires can also result from broken greasewood stems.
Usually less than an inch in length, succulent greasewood leaves are round and have no petilole. They may be hairless or slightly hairy. Deciduous, the leaves grow in early spring and fall after the first fall frost.
Greasewood has both male and female flowers, usually both on the same plant. The male flowers are terminal, conelike and resemble catkins. Male flowers occur on the terminal ends of stems and have no petals or sepals and 2 or 3 stamens. Female flowers appear singly or in pairs in the leaf axils below the male flowers. With 1 pistil and 1 to 3 stigmas, the female flowers are surrounded by bracts in a cuplike perianth (sepals and petals collectively). Greasewood plants are not self-fertile and depend on the wind to distribute the pollen.
The greasewood fruit is a utricle (does not open when mature) with one seed and a thin wall.
Containing oxalates of potassium and sodium, greasewood is moderately poisonous to sheep and cattle if eaten in large quantities. The toxicity increases as the plant matures.
Native Americans used crushed greasewood leaves to treat insect bites. They also cooked and ate young shoots as greens. Oxalates are water soluble and are removed in the cooking water.
Greasewood wood is yellow and hard and makes good firewood. The wood was also used for arrow shafts by indigenous people.
Greasewood readily resprouts after a fire.
The genus name, Sarcobatus, is from the Greek: “sarco” meaning flesh and “batos” meaning bramble. The genus refers to the spiny branches and succulent leaves. Derived from Latin, the species name, vermiculatus, means “worm eaten”. I am not certain why.
These greasewood specimens are growing along California Highway 299 east of Cedarville CA near the Nevada border (Modoc County).