''Poa bulbosa'' is a species of

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 ...

known by the common names bulbous bluegrass or bulbous meadow-grass. It is native to Eurasia and North Africa, but it is present practically worldwide as an

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

. It is widespread in the United States and southern Canada. It was introduced to the eastern United States around 1906 and the western US in 1915 as a contaminant in shipments of

alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as w ...

seed.Novak, S. J. & A. Y. Welfley. (1997)
Genetic diversity in the introduced clonal grass ''Poa bulbosa'' (Bulbous bluegrass).
''Northwest Science'' 71:4 271-80. It was intentionally planted on both the east and west coasts
/ref> to control

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

s and prevent

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

. Today it is a common grass across the continent and is a

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is injurious to agricultural or horticultural crops, natural habitats or ecosystems, or humans or liv ...

in some areas.Missouri Plants Photo Profile
/ref> It is a sturdy, hardy, persistent, aggressive grass that easily outcompetes many other plants and becomes the dominant species in disturbed habitat types, such as

overgrazed Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature rese ...

fields. This is an annual or perennial grass forming dense clumps up to about 60 centimeters tall. The stems are smooth and hollow and usually have bulbous sections at their bases about a centimeter in length. The grass is more likely to have bulbous sections if it is growing in a drier area, and study has indicated the bulbous sections are mostly water. If the bulbous bases are detached and replanted they can give rise to new plants. The

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

is a wide cluster of branches bearing green leaflike spikelets with darker bases that contain

bulbil A bulbil (also referred to as bulbel, bulblet, and/or pup) is a small, young plant that is reproduced vegetatively from axillary buds on the parent plant's stem or in place of a flower on an inflorescence. These young plants are clones of the pa ...

s. Viable seed is rarely produced, and the plant usually reproduces asexually via its basal bulbous sections and via bulbils. Although the plant reproduces vegetatively (asexually) most of the time, it has been shown to possess high

genetic variability Genetic variability is either the presence of, or the generation of, genetic differences. It is defined as "the formation of individuals differing in genotype, or the presence of genotypically different individuals, in contrast to environmentally i ...

. Many types of animals, including wild and domesticated

ruminant Ruminants (suborder Ruminantia) are ungulate, hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by Enteric fermentation, fermenting it in a specialized stomach prior to digestion, principally ...

s, small mammals, and birds, readily consume this grass, especially the bulbils in the inflorescences, which contain some

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets ...

es and

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers spec ...

s. The grass is used as a

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 ...

and a pasture grass in parts of its native region.FAO Ecocrops
/ref>

References

External links

Jepson Manual TreatmentUSDA Plants ProfileGrass Manual TreatmentFlora of New South WalesPhoto gallery
{{Taxonbar, from=Q159237 bulbosa Flora of Lebanon Plants described in 1753 Taxa named by Carl Linnaeus Flora of Malta