| Poa annua | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Monocots |
| (unranked): | Commelinids |
| Order: | Poales |
| Family: | Poaceae |
| Genus: | Poa |
| Species: | P. annua |
| Binomial name | |
| Poa annua L. |
|
Poa annua, or annual meadow grass (known in America more commonly as annual bluegrass), is a widespread low-growing turfgrass in temperate climates. Though P. annua is commonly considered a solely annual plant due to its name, perennial bio-types do exist. 'Poa' is Greek for fodder. It is one of the sweetest grasses for green fodder, but less useful than hay. This grass may have originated as a hybrid between Poa supina and Poa infirma.[1]
It has a slightly creeping, fibrous, rootstock. The stem grows from 15–25 cm high. It is slightly flattened, due to being folded rather than rolled.
The panicle is open and triangular shaped, 5 to 7.5 cm long. The spikelets are stalked, awnless, 1 to 2 cm long when flowering, and loosely arranged on delicate paired or spreading branches. Sometimes they are tinged purple.
The vivid green leaves are short and blunt at the tips, shaped like the prow of a small canoe. They are soft and drooping. Long sheaths clasp the stem. The leaves are smooth above and below, with finely serrated edges. Occasionally the leaves are serrated transversely.
The ligule is pointed and silvery. Compared this to Common Meadowgrass Poa pratensis, which has a squared ligule, and Poa trivialis, which has a pointed, but less silvery ligule.
The leaves are smooth above and below, with finely serrated edges. Occasionally the leaves are serrated transversely.
It is in flower all year around except for severe winters. The seeds ripen and are deposited 8 months of the year. The plant grows rapidly from seed, flowering within 6 weeks, seeding and then dying.[2]
It is a common weed of cultivation, known in the Americas as annual bluegrass.[3] It occurs as a common constituent of lawns, where it is also often treated as a weed, and grows on waste ground. However, it is sometimes the most suitable lawn grass for many sites, and can form most of the entire grass sward in some lawns. On lawns it grows better in rich soils, but is usually small enough to be overlooked. It does not compete with other plants. Many golf putting greens, including the famously fast Oakmont Country Club greens, are planted with this grass,[4] although many courses have converted to bentgrass (Agrostis spp.).