The document discusses and provides visual identification guides for several common winter annual grass weeds in Oklahoma, including rescuegrass, cheat, downy brome, Japanese brome, Italian ryegrass, wild oat, jointed goatgrass, and feral rye. Diagrams and photos show distinguishing characteristics such as ligule shape and size, seedhead features, and hair patterns on leaves and stems to help identify each weed type. Contact information is provided for high resolution photos.

1. Winter annual
grass weed ID
Joe Armstrong
Oklahoma State University

2. All photos, unless noted, were
taken by Joe Armstrong.
If you would like high resolution
versions of these photographs,
please contact Joe at
joe.armstrong@okstate.edu.

3. rescuegrass
Membranous ligule
Dense hairs on seedlings
Diagram: Weeds of the South

4. rescuegrass
Seedheads are flat, awnless

6. cheat
(“true cheat”)
Membranous ligule
Seedhead has awns
weeds.ippc.orst.edu
Diagram: Weeds of the South twig.tamu.edu

7. cheat

9. downy brome Japanese brome
Membranous ligule
Diagram: Weeds of the South

10. downy brome Japanese brome
weeds.ippc.orst.edu weeds.ippc.orst.edu

11. downy brome Japanese brome

12. Italian ryegrass
Membranous ligule
Large, clasping auricles
Shiny, waxy leaves
ALS-resistance
ACCase-resistance??
Diagram: Weeds of the South

13. Italian ryegrass

14. wild oat
Large, jagged
membranous
ligule
Scattered hairs on
leaf and stem
twig.tamu.edu
Diagram: Weeds of the South

15. wild oat
calphotos.berkeley.edu
twig.tamu.edu

17. jointed goatgrass
Short, membranous
ligule
Sparse, stiff hairs on
leaf margins
twig.tamu.edu jointedgoatgrass.wsu.edu
Diagram: Weeds of the South

21. jointed goatgrass
Can hybridize with wheat
jointed
wheat hybrid goatgrass
twig.tamu.edu

22. feral rye
Small, membranous ligule
May have small auricles
Grows taller than wheat

23. feral rye