''Poa'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of about 570

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...

es, native to the temperate regions of both hemispheres. Common names include meadow-grass (mainly in Europe and Asia), bluegrass (mainly in North America), tussock (some

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

species), and speargrass. ''Poa'' () is Greek for "

fodder Fodder (), also called provender (), is any agriculture, agricultural foodstuff used specifically to feed domesticated livestock, such as cattle, domestic rabbit, rabbits, sheep, horses, chickens and pigs. "Fodder" refers particularly to food g ...

". ''Poa'' are members of the subfamily

Pooideae The Pooideae are the largest subfamily of the grass family Poaceae, with about 4,000 species in 15 tribes and roughly 200 genera. They include some major cereals such as wheat, barley, oat, rye and many lawn and pasture grasses. They are often r ...

of the family

Poaceae Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...

. Bluegrass, which has green leaves, derives its name from the seed heads, which are blue when the plant is allowed to grow to its natural height of two to three feet (0.6 to 0.9 meters). The genus ''Poa'' includes both annual and

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

species. Most are

monoecious Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy is conne ...

, but a few are

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

(separate male and female plants). The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are narrow, folded or flat, sometimes bristled, and with the basal sheath flattened or sometimes thickened, with a blunt or hooded apex and membranaceous

ligule A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (Poaceae) and sedges. A ligule is also a strap-shaped extension of the corolla, such as that of a ...

Cultivation and uses

Many of the species are important

pasture Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep, or swine ...

plants, used extensively by

grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other ...

livestock Livestock are the domesticated animals raised in an agricultural setting to provide labor and produce diversified products for consumption such as meat, eggs, milk, fur, leather, and wool. The term is sometimes used to refer solely to animals ...

Kentucky bluegrass ''Poa pratensis'', commonly known as Kentucky bluegrass (or blue grass), smooth meadow-grass, or common meadow-grass, is a perennial species of grass native to practically all of Europe, North Asia and the mountains of Algeria and Morocco. Altho ...

(''Poa pratensis'') is the most extensively used cool-season grass used in

lawn A lawn is an area of soil-covered land planted with grasses and other durable plants such as clover which are maintained at a short height with a lawnmower (or sometimes grazing animals) and used for aesthetic and recreational purposes. L ...

s, sports fields, and

golf course A golf course is the grounds on which the sport of golf is played. It consists of a series of holes, each consisting of a tee box, a fairway, the rough and other hazards, and a green with a cylindrical hole in the ground, known as a "cup". Th ...

s in the United States.

Annual bluegrass ''Poa annua'', or annual meadow grass (known in America more commonly as annual bluegrass or simply poa), is a widespread low-growing turfgrass in temperate climates. Notwithstanding the reference to annual plant in its name, perennial bio-types ...

(''Poa annua'') can sometimes be considered a weed. According to second-century physician

Galen Aelius Galenus or Claudius Galenus ( el, Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen () or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one of ...

, the roots of certain species are good for treating fresh wounds and bleeding. In the sixteenth century, ''Poa'' grasses were used to treat inflammation of the kidney. Some of the ''Poa'' species are popular for gardens and for landscaping in

Insect foodplant

Lepidoptera Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

whose caterpillars feed on ''Poa'' include: *''

Agriphila inquinatella :''The name ''Agriphila inquinatella'' has been misapplied to some related species in the past; see below for details.'' ''Agriphila inquinatella'' is a small moth species of the family Crambidae. It is found in Europe, around the Caucasus area t ...

'' *''

Cercyonis pegala The common wood-nymph (''Cercyonis pegala'') is a North American butterfly in the family Nymphalidae. It is also known as the wood-nymph, grayling, blue-eyed grayling, and the goggle eye. Description The common wood-nymph can vary greatly. A ...

'' (common wood-nymph) *''

Poanes hobomok The Hobomok skipper (''Lon hobomok'') is a North American butterfly of the family Hesperiidae. Description This small butterfly has slim, triangular wings. The upper side of the male's wings is mostly orange with the margins being dark brown. ...

'' (Hobomok skipper) *''

Poanes zabulon The Zabulon skipper (''Lon zabulon'') (sometimes called the southern dimorphic skipperJames A. Scott (1986). ''The Butterflies of North America''. Stanford University Press, Stanford, CA. ) is a North American butterfly first described by the ...

'' (Zabulon skipper)

Selected species

References

{{Authority control Poaceae genera Lawn grasses Taxa named by Carl Linnaeus