Juncus acutus
# Juncus acutus

Juncus acutus, the spiny rush, sharp rush or sharp-pointed rush, is a flowering plant in the monocot family Juncaceae. It is native to the Americas, Northern and Southern Africa, Western and Southern Europe and West Asia, and is found in a variety of wet habitats, such as bogs, fens, meadows, and salt marshes, and along the edges of ponds and lakes.

The sharp-pointed rush is a perennial plant that grows to a height of about 60 to 100 centimeters (24 to 39 inches). It has slender, cylindrical stems with narrow, pointed leaves and clusters of small, light brown flowers that bloom in the summer.

This species is important for a variety of reasons. It provides habitat and food for a range of wetland animals, including insects, birds, and mammals. It is also an important component of wetland ecosystems, helping to prevent soil erosion and maintain water quality. In some countries like Australia it is considered to be an invasive weed and the spines harmful to young children.

In addition, sharp-pointed rush has been used for a variety of purposes, including as a source of fiber for making paper, baskets, and other woven products, and for medicinal purposes. The plant has also been used for landscaping and erosion control, as well as for ornamental purposes in gardens and wildflower meadows.

Despite its ecological and cultural significance, Juncus acutus is considered to be of least concern in terms of conservation, as it is widely distributed and not currently threatened by habitat loss or other factors. However, continued conservation efforts are necessary to protect this species and its habitat and ensure its long-term survival.

## 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 tussock-forming perennial that can grow to 1.5 metres (4.9 ft) 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 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. The flowers are hermaphrodite and are pollinated by the wind.

### 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.

### Roots

    Short and robust rhizomes.

## Gallery

* Habit
* Inflorescence
* 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.

