Barb goatgrass and medusahead are invasive annual grasses that have spread or have the potential to spread throughout much of California's annual grasslands. Barb goatgrass is a B-rated noxious weed and medusahead is a C-rated noxious weed in the State of California, meaning that they both cause economic or environmental detriment. Both are prolific seed producers, making management to reduce their abundance possible but eradication difficult and unlikely. This publication gives a thorough description of growth stages of these invasive plants so you can employ the optimum timing of grazing and mowing treatments for management in your situation. Includes color photographs of key growth stages.