Poa annua L.

Annual Bluegrass; Low Speargrass

Herb

Annual

Vascular

Annual Bluegrass is an introduced annual in the Grass family (Poaceae). It is native to Eurasia but has become established worldwide. Annual Bluegrass can be found throughout Alabama. It occurs in lawns, on roadsides, along streams, in fallow fields, and in other moist disturbed sites. It is a cool season annual bunch grass. Germination occurs in the late fall and early winter as day time temperatures fall below 70 degrees. Annual Bluegrass has a fibrous root system. It forms small clumps up to 10 inches in height. The plant branches from the base to produce short prostrate to erect stems. The leaves are alternate, bright green in color, glabrous, with finely serrate margins. The tip of the leaf is prow-shaped. Flowers are produced in open, triangular panicles. The spikelets are laterally compressed. The seed is a grain. Annual Bluegrass is a major weed throughout the world. It is particularly a problem in lawns and on golf courses. The plants die in the spring leaving unsightly brown dead patches in lawns. Annual Bluegrass is highly variable and consists of annual bunch forms and perennial rhizomatous forms. It is believed that Annual Bluegrass is of hybrid origin with Weak Bluegrass (Poa infirma Kunth) and Supine Bluegrass (Poa supina Schrad.) as the parents. Annual Bluegrass is similar to Chapman's Bluegrass (Poa chapmaniana Scribner), another annual species. Chapman's Bluegrass is a native species that usually prefers drier sites than Annual Bluegrass. It has lemmas that are cottony webbed at the base.--A. Diamond

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Not Native FAC (NWPL)

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