Organizations work toward management, elimination of new invasive grasses

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SHERIDAN — Two new invasive grasses have been found in Sheridan County.

Luke Sander from Sheridan County Weed and Pest said the two species of grasses, vetenata and medusahead, were spotted last summer. He said that while there was an early case where vetenata was found by a botanist in 1997, no action was ever taken to control it.

When the University of Wyoming was conducting studies last summer, they found more of it.

“It turns out, vetenata’s fairly widespread,” Sander said, “More so than we thought in Sheridan County.”

Sander said medusahead was found later in the summer. As the first time the species has ever been found in Wyoming or in this ecoregion, Sander said that this summer it’ll be a big priority for Weed and Pest to identify where the grass is and start treatments.

The two invasive grasses, he said, have similar effects as cheatgrass, increasing wildfire frequency and intensity. But vetenata and medusahead are even more detrimental.

He said they impact rangelands, exclude desirable native species and reduce livestock and wildlife forage by up to 70 percent. He also said the higher silica content in the two grasses makes them less palatable to grazing.

“They kind of just take over,” Sander said. “Of the areas in the US that have them, they’re reported to be worse than cheatgrass, just the invasiveness of it and the reduced grazing.”

Courtesy Photo | Sheridan County Weed and Pest
One of the new invasive grasses, ventenata is considered worse than cheatgrass and have been observed as replacing cheatgrass.


Sander said they’re not certain how the species spread to Sheridan. He said medusahead has been found on two pieces of state land in the county that’s accessible to the public, so it’s possible out-of-state travelers brought it in unknowingly. This summer’s survey work will help put together a clearer picture of the situation.

The first step is raising awareness of the grasses. District Manager of Sheridan County Conservation District Carrie Rogaczewski said they are helping spread the word. Information about the species, along with photos, can be found on SCCD’s website and will be on Weed and Pest’s soon.

Weed and Pest, UW and SCCD are also working with many other entities, including the U.S. Department of Agriculture, Wyoming Game and Fish and Bureau of Land Management, as part of the North East Wyoming Invasive Grass Working Group to address these issues.

Sander said starting around April they’ll start to hold public meetings, and he encourages anyone who sees the grasses to report them to their county’s Weed and Pest or through the website EDDMapS – Early Detection and Distribution Mapping System.

The two grasses, Sander said, are a bit difficult to identify, but vetenata is similar in appearance to cheatgrass, only with longer awns. He said medusahead is more identifiable and looks similar to foxtail barley with an inflorescent light green color when it grows in the summer.

Once public meetings start, he said, it’ll be easier for people to identify the grasses. If people find themselves in areas with the grasses, they should clean boots, pets and animals to help keep them from spreading. But most importantly, notify Weed and Pest.

“The biggest thing, I guess, would be to report it,” Sander said, “so we can start managing of it and eliminate it before it gets worse.”

By |February 23rd, 2017|

About the Author:

Chelsea Coli joined The Sheridan Press in October 2016 as the county government, business and outdoors reporter. Coli has a master’s in journalism from Georgetown University and a bachelor’s from the University of Nebraska-Lincoln. Before moving to Wyoming, Coli taught English through the LADO International Institute and worked as an intern and copywriter for Ruby Studio in Colombo, Sri Lanka.