Poa bulbosa
Encyclopedia
Poa bulbosa is a species of grass
known by the common name bulbous bluegrass. It is native to Eurasia and North Africa, but it is present practically worldwide as an introduced species
. 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
seed. It was intentionally planted on both the east and west coasts to control weed
s and prevent erosion
. Today it is a common grass across the continent and is a noxious weed in some areas. 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
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
is a wide cluster of branches bearing green leaflike spikelets with darker bases that contain bulbils. Viable seed is rarely produced, and the plant usually reproduces asexually
via its basal bulbous sections and via bulbils. Although the plant reproduces vegetatively (asexaully) most of the time, it has been shown to possess high genetic variability
.
Many types of animals, including wild and domesticated ruminant
s, small mammals, and birds, readily consume this grass, especially the bulbils in the inflorescences, which contain some starch
es and fat
s. The grass is used as a fodder
and a pasture grass in parts of its native region.
Poaceae
The Poaceae is a large and nearly ubiquitous family of flowering plants. Members of this family are commonly called grasses, although the term "grass" is also applied to plants that are not in the Poaceae lineage, including the rushes and sedges...
known by the common name bulbous bluegrass. It is native to Eurasia and North Africa, but it is present practically worldwide as an introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
. 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
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
seed. It was intentionally planted on both the east and west coasts to control weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
s and prevent erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...
. Today it is a common grass across the continent and is a noxious weed in some areas. 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
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, or by overpopulations of native or non-native wild animals.Overgrazing reduces the...
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
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a wide cluster of branches bearing green leaflike spikelets with darker bases that contain bulbils. Viable seed is rarely produced, and the plant usually reproduces asexually
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
via its basal bulbous sections and via bulbils. Although the plant reproduces vegetatively (asexaully) most of the time, it has been shown to possess high genetic variability
Genetic variability
Genetic variability is a measure of the tendency of individual genotypes in a population to vary from one another. Variability is different from genetic diversity, which is the amount of variation seen in a particular population. The variability of a trait describes how much that trait tends to...
.
Many types of animals, including wild and domesticated ruminant
Ruminant
A ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...
s, small mammals, and birds, readily consume this grass, especially the bulbils in the inflorescences, which contain some starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
es and fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
s. The grass is used as a fodder
Fodder
Fodder or animal feed is any agricultural foodstuff used specifically to feed domesticated livestock such as cattle, goats, sheep, horses, chickens and pigs. Most animal feed is from plants but some is of animal origin...
and a pasture grass in parts of its native region.