It has been a dry, dry summer and driving north of Elko the sagebrush looks gray, and half dead. But bright yellow bands of blooming rabbitbrush border the highway on both sides. Looking across the sagebrush flats, it is also easy to see just where rabbitbrush grows by the bright yellow flowers mixed in with the gray sagebrush.
These blooming rabbitbrush plants may be either of two native species. The choices are rubber rabbitbrush, also called chamisa, gray, or golden; and yellow rabbitbrush, also called green or Douglas.
The photo shows a rare occurrence with both species growing next to each other. The way to distinguish rubber rabbitbrush is that the leaves and stems look gray since they are covered with fine hairs. This adaptation helps them reduce evaporation of vital water. The dull, grayish plant on the right shows these fine hairs. The plant on the left has bright green leaves and stems, showing it is a yellow rabbitbrush. The rabbitbrush bordering the highway is probably yellow rabbitbrush based on their green look beneath the bright yellow flowers.
Doing an Internet search on rabbitbrush shows a plant that is not highly regarded. The main problem is cattle do not eat much of it. But wildlife such as mule deer, antelope, elk, small mammals and birds do eat it. They make use of the stems, leaves, flowers and seeds, especially during winter. The plants also provide cover for small mammals and birds such as jackrabbits and sage grouse.
Humans use both types for restoration of damaged sites like strip mines, road cuts, and severely deteriorated rangeland since rabbit rush establishes easily and grows rapidly. Rabbitbrush will also increase quickly after fire or a heavy disturbance. Homeowners use rabbitbrush as an ornamental xeriscaping shrub in areas where water conservation is important. It thrives in a wide range of coarse, alkaline soils.
Rubber rabbitbrush has been studied as a source of rubber as early as 1904 and especially during World Wars I and II. The University of Nevada is conducting research on possible uses of rubber rabbitbrush for biomaterial and bioenergy uses. One possible commercial use of rubber rabbitbrush could be to produce hypoallergenic rubber for people with latex allergies.
Those wishing to control the amount of rabbitbrush find it is not so easy since they have a deep tap root. Cutting or mowing removes only the top of the plant and the roots quickly sprout new shoots and stems. Rabbitbrush roots must be completely removed to control the plant. It also usually increases in density following fire so prescribed burning is not much help in controlling it. Chemical spraying is about the only control method that works.
Rabbitbrush’s long taproot explains why specimens growing in near Los Alamos, New Mexico register on a Geiger counter. They contain a concentration of radioactive strontium-90 that is 300,000 times higher than a normal plant. Their deep tap roots have reached down into a closed nuclear waste treatment area. The plants take up strontium instead of calcium due to similar chemical properties. Only a Geiger counter distinguishes these radioactive shrubs from others.