It’s time for another column on plants. Many different grasses occur in southern Idaho but when it comes to forage value and integrity of the ecosystem, not all grasses are created equal.
Some are problematic, like bulbous bluegrass, while others are flat out problems, like cheatgrass, but more on this in another column. Today, we’ll take a look at some of the most beneficial, and in my opinion most beautiful, rangeland plants, our native bunchgrasses.
A bunchgrass is just what it sounds like, a perennial grass that grows in clumps (bunches). Unlike sod-forming grasses which grow from networks of roots (think most lawn grasses), bunchgrass develops as a cluster of numerous tightly packed growing points. Leaves and flower stems grow from these points. Bunchgrass leaves die each year, but the plants regrow from the same root system and base each spring. The older the plant, the more growing points it accumulates and the larger the bunch becomes.
Bunchgrasses provide important forage for wildlife and livestock. These plants also afford critical hiding cover for many wildlife species including pronghorn fawns and sage-grouse chicks. A complete discussion of bunchgrasses would take a book, so I’ll just touch on some characteristics of four native bunchgrasses commonly found in eastern Idaho: bluebunch wheatgrass, Indian ricegrass, needle-and-thread grass, and squirreltail.
Bluebunch wheatgrass grows 1½ to 4 feet tall with an extensive root system. Bluebunch is palatable and a preferred forage for cattle, horses, sheep, elk, deer, and pronghorn at various times of the year. Protein levels in spring can be as high as 20 percent but decrease to about 4 percent as the grass matures. Bluebunch wheatgrass is most abundant in our 8 to 20-inch annual precipitation zones. It is a major component of many of our native plant communities, often the most dominant species by weight.
Indian ricegrass is adapted to relatively dry sites, but can also be found in moist areas within drier environments. Native Americans used Indian ricegrass seeds for food. This grass is an important forage for wildlife and livestock. This bunchgrass is often 1 to 2½ feet tall with leaves tightly rolled from the edges, so each leaf looks like a straight, skinny tube. The inflorescence (arrangement of flowers) consists of long, waving stalks that look like hairs. Each branch terminates in a single seed. The seed is black and covered with short hairs. Indian ricegrass is planted to help control wind erosion in restoration projects. It may be used in landscaping, but requires well-drained soil.
Needle-and-thread grass is normally 1-4 feet tall with erect, smooth hollow stems and flat leaves, 8-12 inches long. Needle-and-thread grass provides good forage during spring before seeds develop and again during fall after seeds have dropped, especially after fall rains. It is important for deer during spring, and elk in winter, providing a good source of energy. It cures well to provide fall and winter forage for livestock. When grazed while awned seeds are present (seeds with stiff bristles), the sharp-pointed seed may injure livestock by working into tongue, throat, eyes, and ears.
Squirreltail is often considered a minor forage species for livestock during summer within sagebrush habitats, but can provide palatable winter forage for domestic sheep. Squirreltail provides forage for mule deer, pronghorn, ground squirrels, and rabbits. Like Indian ricegrass, the mature awns of squirreltail may cause inflammation around the mouth of grazing animals.
Most conservation challenges center around fire and invasive plants. Native grasses can be crowded out by cheatgrass and other invasive species and damaged by increasing fire frequency.
The next time travel through our sagebrush landscapes to enjoy local wildflowers, take a minute to appreciate the wonderful diversity and beauty of our native grasses.