The scientific name given to annual bluegrass, a low-growing and cool-season grass which dies in early summer as the soil top layer begins to dry. Poa annua is distinguished from other grasses by its typical leaf tip shaped like a boat's bow. Annual bluegrass is considered a winter-annual grassy weed that produces numerous seeds spread easily by birds and man. Poa annua is a difficult-to-control grassy weed that requires specialized products and properly-timed applications. Depending on the turf species, the only choice for control may be the use of non-selective weed control products.