Foster Creek Conservation District
Foster Creek Conservation District

Be on the Lookout for these Unwanted Invaders!

Photo Credit C.D Carr

There are two grasses, Ventenata (aka Wiregrass) Ventenata dubia, and Medusahead Rye Taeniatherum caput-medusae, that are not wanted in Douglas County! These non-native winter annual grasses are spreading to more areas of the Pacific Northwest and competing with native vegetation. 


Both grasses cause serious degradation to rangeland, especially the shrub steppe of Washington, displacing native plant species and desirable high-quality forage. Medusahead and Ventenata both have very high silica content—making them unpalatable for livestock and wildlife—and are both of low nutritional value. 


Much like Cheatgrass, Medusahead and Ventenata grow in very thick stands and create thick thatch layers on the ground, starving the soil and native plants of nutrients. These thick stands of grass and thatch also greatly increase wildfire danger, change wildfire regimes, and can lead to more fragmented ecosystems such as what has occurred in the Sagebrush Steppe


Photo Credit C.D. Carr

 In the spring Medusahead typically remains green two weeks longer than cheatgrass. The sharp awns make Medusahead dangerous to livestock. Medusahead has long, erect awns that can be up to 4 inches long, and often become twisted as well as long glumes that remain after seeds fall and look like sharp bristles later in the season. It blooms in the spring and stems can grow up to 2.3 feet tall.

Ventenata has small, wispy seed heads and an open, airy panicle on slim stems of 6 to 29 inches tall. It flowers from June to August about a month later than Bromus species such as Cheatgrass. Some florets have bent awns while others are straight. Some of the easiest features to identify it by are its uniquely long ligule and reddish-black nodes on the stem.

Please keep an eye out for these grass species, notify the district if you see them, and be careful not to spread the seeds.

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Foster Creek Conservation District 203 S Rainier Waterville, WA 98858 509-888-6372 © Foster Creek CD