''Alopecurus geniculatus'' 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 name water foxtail or marsh foxtail. It is native to much of

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...

and introduced into

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

, and

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. It grows in moist areas. ''Alopecurus geniculatus'' is a

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 ...

grass forming bunches of erect stems up to about 60 cm (24 inches) in height. The leaves are up 12 cm (5 inches) in length. The pale green to purplish

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 dense

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

up to 6 or 7 cm long which blooms in dusty yellow-orange

anthers The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filam ...

.Dogan, M. 1999. A concise taxonomic revision of the genus ''Alopecurus'' L. (Gramineae). Türk Botanik Dergisi 23(4): 245–262 reproduces sexually by seeds and can reproduce vegetatively by rooting at stem nodes.

Environmental conservation

''Alopecurus geniculatus'' is a component of

purple moor grass and rush pastures Purple moor grass and rush pastures is a type of Biodiversity Action Plan habitat in the UK. It occurs on poorly drained neutral and acidic soils of the lowlands and upland fringe. It is found in the South West of England, especially in Devon ...

a type of Biodiversity Action Plan habitat in the UK. It occurs on poorly drained neutral and acidic soils of the lowlands and upland fringe.

Nonindigenous spread

The grass has spread significantly in the United States since it was first introduced.

Hybrid

''Alopecurus geniculatus'' is known to hybridize with other members of the ''Alopecurus'' genus. ''Alopecurus x haussknechtianus'' is a hybrid between ''A. geniculatus'' and ''A. aequalis'', ''Alopecurus x brachystylus'' is a hybrid between ''A. geniculatus'' and ''A. pratensis'', ''Alopecurus x plettkei'' is s hybrid between ''A. geniculatus'' and ''A. bulbosus'' (Botanical Society of Britain and Ireland 2016)

References

External links

Jepson Manual TreatmentUnited States Department of Agriculture Plants ProfileGrass Manual TreatmentCalphotos Photo gallery, University of California
geniculatus Bunchgrasses of Asia Bunchgrasses of Europe Plants described in 1753 Taxa named by Carl Linnaeus {{Pooideae-stub