annual bluegrass, annual blue grass, walkgrass
- Poa annua is an erect or clump-forming annual grass that tolerates close mowing, or may reach 11 in. (27.9 cm) in height. It can also be identified by having light green grass with a boat-shaped leaf tip that resembles other lawn and turf grass species. This weed is very similar to Kentucky Bluegrass (Poa pratensis), but is much lighter in color and lacks rhizomes.
- Leaves are light green in color, especially when compared to the dark green color of other closely related turfgrass species (for example Kentucky Bluegrass, Poa pratensis). Leaf blades are 0.5-5 in. (1.3–12.7 cm) long, 0.04-0.2 in. (1-5 mm) wide, folded in the bud and lack hairs on either surface.
- The seed head is an open panicle, 0.75-2.5 in. (1.9-6.4 cm) long, and pyramidal in outline.
- Fruit is an achene.
- Ecological Threat
- Poa annua is primarily a weed of lawns and turfgrass, found throughout the United States.
- Global Invasive Species Database. 2011. Invasive Species Specialist Group (ISSG) of the IUCN Species Survival Commission
- Texas AgriLife Extension Service, Texas A&M System
- University of California, Jepson Flora Project
- Virginia Tech Weed Identification Guide
- USDA NRCS PLANTS
- USDA ARS GRIN
Images from Bugwood.org