Juncus Acutus

''Juncus acutus'', the spiny rush, sharp rush or sharp-pointed rush, is a flowering plant in the monocot family Juncaceae found throughout the Americas, Northern and Southern Africa, Western and Southern Europe and West Asia.

It grows in salt marshes and on dunes and is reliable for reducing erosion rates.
In some countries like Australia it is considered to be an invasive weed and the spines harmful to young children.

Synonyms

*''Juncus acutus'' ssp. ''leopoldii'' (Parl.) Snog. -- Leopold's rush
*''Juncus acutus'' L. var. ''sphaerocarpus'' Engelm
*''Juncus acutus'' L. subsp. ''acutus''
*''Juncus spinosus'' Forssk
*''Juncus acutus'' ssp. ''leopoldii'' also known as ''Leopold's rush'' is a native of Arizona, California, Georgia and Nevada.
*''Juncus acutus'' L. var. ''conglobatus'' Trautv
*''Juncus acutus'' L. var. ''decompositus'' Guss
*''Juncus acutus'' L. var. ''longibracteatus'' Buchenau

Description

''Juncus acutus'' is a brown and green
" tussocky"
perennial that can be to
tall in all kinds of soils,
in areas which go from extremes in flood and dry like dunes
or that just stay wet like lowland grassland and grassy woodland, riparian vegetation, freshwater wetland, and saline and subsaline wetlands.
;Stems and leaves: Pith filled stems and leaves arise from the base at different angles giving the plant a globe shape. The leaves form a basal sheath around the flower stem leaves and end with a stiff sharp point.
;Flowers: The flower stems are to in diameter and to long and are similar to the leaves. They emerge from the base at all angles and each have 1 - 6 flowers. Each flower has 6 stamens and to long bracts that terminate in a stiff and sharp point. The flowers are hermaphrodite and are pollinated by the wind.
;Fruits and reproduction: Fruits are oval 3-celled brown capsules to . The to long brown seeds have a tail at each end.
;Roots: Short and robust rhizomes.

Gallery

Image:Juncus acutus3.jpg , Habit
Image:Juncus acutus seeds at Lake Walyungup, Rockingham Lakes Regional Park, June 2022 01.jpg, Inflorescence
Image:Juncus acutus leaf tip NC2.jpg, Sharp leaf tip of Juncus acutus

Distribution

Found principally in low-lying damp, low fertility areas like sandy sea shores and dune slacks and coastal flats, occasionally in salt marshes and disturbed saline areas, mine dumps, lowland grassland and grassy woodland, riparian vegetation, freshwater wetland, and saline and subsaline wetlands
:Palearctic:
::Northern Africa: Algeria, Egypt, Morocco
::Western Asia: Iran, Iraq, Israel, Jordan, Lebanon, Turkey
::Caucasus: Armenia, Azerbaijan, Georgia
::Northern Europe: British Isles
::Southeastern Europe: Albania, Crete, Greece, Italy, Kosovo, Montenegro, Sardinia, Serbia, Sicily, Malta
::Southwestern Europe: Azores, Balearic Islands, Corsica, France, Portugal, Spain
:Nearctic:
::Northern America: Baja California

Community species

:In Brazil, ''J. acutus'' has been observed on the Santa Catarina coast living in communities with:
:*'' Ipomoea pes-caprae''
:*''Hydrocotyle bonariensis''
:*''Senecio crassiflorus''
:In a natural shallow depression in the Murray River floodplain in South Australia:
:*'' Muehlenbeckia florulenta''
:*'' Atriplex semibaccata''
:*''Halosarcia pergranulata'' ssp. ''pergranulata''
:*'' Mimulus repens''
:*'' Ludwigia peploides'' ssp. ''montevidensis''
:*''Phragmites australis''
:*''Paspalum vaginatum''

Chemistry

The dimeric phenanthrenoid 8,8'-bidehydrojuncusol and the monomeric juncusol and dehydrojuncusol can be isolated from ''J. acutus''.

References

External links

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{{Taxonbar, from=Q2094325

acutus
Halophytes
Palearctic flora
Flora of South America
Flora of North America
Flora of Baja California
Flora of Brazil
Flora of Europe
Plants described in 1753
Taxa named by Carl Linnaeus