bio.wikisort.org - Plant

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.[2]

Juncus acutus
Lake Walyungup, Rockingham Lakes Regional Park
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Monocots
Clade:	Commelinids
Order:	Poales
Family:	Juncaceae
Genus:	Juncus
Species:	J. acutus
Binomial name
Juncus acutus L.[1]

It grows in salt marshes[3] and on dunes[4] and is reliable for reducing erosion rates.[5] In some countries like Australia it is considered to be an invasive weed[6] and the spines harmful to young children.[7]

Synonyms

• Juncus acutus ssp. leopoldii (Parl.) Snog. -- Leopold's rush[8]
• Juncus acutus L. var. sphaerocarpus Engelm[9]
• Juncus acutus L. subsp. acutus
• Juncus spinosus Forssk[10]
• Juncus acutus ssp. leopoldii also known as Leopold's rush is a native of Arizona, California, Georgia and Nevada.[1][9]
• Juncus acutus L. var. conglobatus Trautv
• Juncus acutus L. var. decompositus Guss
• Juncus acutus L. var. longibracteatus Buchenau[11]

Description

Juncus acutus is a brown and green[12] "tussocky"[7] perennial that can be to 1.5 metres (4.9 ft)[12] tall in all kinds of soils,[13] in areas which go from extremes in flood and dry like dunes[4] or that just stay wet like lowland grassland and grassy woodland, riparian vegetation, freshwater wetland, and saline and subsaline wetlands.[14]

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.[7]

Flowers

The flower stems are 2 millimetres (0.079 in) to 4 millimetres (0.16 in) in diameter and 4 centimetres (1.6 in) to 13 centimetres (5.1 in) 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 4 centimetres (1.6 in) to 25 centimetres (9.8 in) long bracts that terminate in a stiff and sharp point.[7] The flowers are hermaphrodite and are pollinated by the wind.[13]

Fruits and reproduction

Fruits are oval 3-celled brown capsules 4 millimetres (0.16 in) to 6 millimetres (0.24 in). The 1.2 millimetres (0.047 in) to 2 millimetres (0.079 in) long brown seeds have a tail at each end.[7]

Roots

Short[7] and robust rhizomes.[12]

Gallery

• 
  Habit
• 
  Inflorescence
• 
  Sharp leaf tip of Juncus acutus

Distribution

Found principally in low-lying damp, low fertility areas[14] like sandy sea shores and dune slacks and coastal flats,[14] occasionally in salt marshes[13] and disturbed saline areas, mine dumps, lowland grassland and grassy woodland, riparian vegetation, freshwater wetland, and saline and subsaline wetlands[14]

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[1]

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[4]

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^{[citation needed]}

Chemistry

The dimeric phenanthrenoid 8,8'-bidehydrojuncusol and the monomeric juncusol[15] and dehydrojuncusol can be isolated from J. acutus.[16]

References

External links

• UniProt. "Juncus acutus". Retrieved 2008-04-25.
• Linné, Carl von; Laurentii Salvii (1753). "Juncus". Species plantarum :exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas... Vol. 1. QK91.C480 1753.
• Missouri Botanical Garden. "Juncus acutus L." Tropicos. Retrieved 2008-04-25.

На других языках

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- [en] Juncus acutus

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[es] Juncus acutus

El junco espinoso (Juncus acutus (L.) Torr. ex Retz. es una especie botánica de fanerógama de la familia de las juncáceas.

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[ru] Ситник острый

Ситник острый (лат. Juncus acutus) — типовой вид рода Ситник.

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