How does it spread?
Roughstalk Bluegrass has two means of reproduction and spread, by stolon’s or above grown creeping stems and seed heads. The majority of spread in Cereal grain crops is by seed but for forages and turf stolon’s can be the main way this weed can spread.

Roughstalk Bluegrass close up picture
Identification
Roughstalk Bluegrass is very similar to turf bluegrass species. However, Roughstalk Bluegrass leaves are folded in the bud and have a membranous ligule that can be absent or be very long. “Rough” stalk Bluegrass gets its name from small hairs on the leaf surface and margin. This bluegrass, like turf-type bluegrasses, has a broad collar and a boat-shaped leaf tip. Roughstalk Bluegrass has yellow-green leaves that are shiny. The leaves can turn red during drought and heat stress. The plant goes to seed from mid-May to June, with an open panicle, like Kentucky Bluegrass.
Source : osu.edu