The first of two workshops on the threat posed by so-called old-world bluestem grasses will be Friday at the Kansas State University Agricultural Research Center.

The workshop is from 9 a.m. to 3 p.m. There is a $10 registration cost to attend.

Two species of old-world bluestem grasses, known as yellow and Caucasian, are considered to be among the the greatest long-term invasive threats to the integrity of native prairie in Kansas and the central Great Plains, according to a flier used to advertise the workshop.

If the spread of the grasses continues as it has in some areas of western Oklahoma and Texas, the grass will be more difficult to control than other invasive species.

The grasses first were brought to the United States in the 1920s from Asia, for use in isolated settings. But they ultimately were added to seed mixes in Kansas in the 1950s.

Livestock avoid grazing the grasses, preferring instead more palatable grasses.

Speakers include Karen Hickman, a professor at Oklahoma State University in Stillwater, who conducted her doctorate thesis at KSU on the grasses.

Fort Hays State University assistant professor Mitch Greer and KSU professor Keith Harmoney also will speak.

Anyone with questions can call Jim Strine, a director of the Kansas Wildlife Federation, one of the workshop sponsors. He can be reached at (785) 625-8940.