Juncus

Juncus
Habit of J. conglomeratus
Flower of J. squarrosus showing: 6 spreading tepals, anthers (upright yellow, held on white filaments), ovary (green) with stigma (pinkish tip column) and styles (white)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Juncaceae
Genus: Juncus
L.
Type species
Juncus acutus
Synonyms
  • Agathryon (Raf.) Záv.Drábk. & Proćków, nom. superfl.
  • Alpinojuncus Záv.Drábk. & Proćków
  • Australojuncus Záv.Drábk. & Proćków
  • Boreojuncus Záv.Drábk. & Proćków, nom. superfl.
  • Cephaloxys Desv.
  • Juncastrum Fourr., not validly published
  • Juncinella Fourr., not validly published
  • Marsippospermum Desv.
  • Microschoenus C.B.Clarke
  • Phylloschoenus Fourr., not validly published
  • Rostkovia Desv.
  • Tenageia (Dumort.) Fourr.
  • Tristemon Raf. (1838)
  • Verojuncus Záv.Drábk. & Proćków

Juncus is a genus of monocotyledonous flowering plants, commonly known as rushes. It is the largest genus in the family Juncaceae, containing around 340 species.

Description

Rushes of the genus Juncus are herbaceous plants that superficially resemble grasses or sedges. They have historically received little attention from botanists; in his 1819 monograph, James Ebenezer Bicheno described the genus as "obscure and uninviting".

The form of the flower differentiates rushes from grasses or sedges. The flowers of Juncus comprise five whorls of floral parts: three sepals, three petals (or, taken together, six tepals), two to six stamens (in two whorls) and a stigma with three lobes. The stems are round in cross-section, unlike those of sedges, which are typically somewhat triangular in cross-section.

In Juncus section Juncotypus (formerly called Juncus subg. Genuini), which contains some of the most widespread and familiar species, the leaves are reduced to sheaths around the base of the stem and the bract subtending the inflorescence closely resembles a continuation of the stem, giving the appearance that the inflorescence is lateral.

Distribution and ecology

Juncus has a cosmopolitan distribution, with species found throughout the world, with the exception of Antarctica. They typically grow in cold or wet habitats, and in the tropics, are most common in montane environments. While typically described as a wind-pollinated genus, recent evidence suggests that some species may be partially insect pollinated.

Juncus species often prefer wetland habitats, such as salt marshes and seeps. For this reason, they often interact with water-borne pollutants and are therefore suspected to uptake these pollutants when they are present in the environment. Research suggests strategic planting of Juncus species may be an effective tactic to clean contaminated water through biotic methods.

Juncus species are important members of the ecosystems they inhabit, providing food and creating habitat for many other organisms, including microbes, insects, amphibians, fish, and birds. Certain species have also been shown to alter the often heavily waterlogged soils they grow in around their roots, increasing the oxygen concentration and changing the pH. Beyond this, Juncus species across their range have been used in diverse ecological studies, including those relating to precipitation effects on marsh species, salt tolerance in brackish wetland plants, the effects of Juncus presence on plant diversity, and the effects of wetland plants on microbial soil communities.

Selected Juncus Habitats
Juncus articulatus in wetland habitat, Germany
Juncus sp. in wetland habitat, Turkey
Juncus acutus in wetland habitat, Uruguay
Juncus rigidus in riparian habitat, Oman
Juncus effusus in grassland habitat, Poland

Fossil record

Several fossil fruits of a Juncus species have been described from middle Miocene strata of the Fasterholt area near Silkeborg in Central Jutland, Denmark.

Uses

Species of genus Juncus are used by cultures around the world for various purposes. The fibrous stems lend themselves to making cordage, and cultures including indigenous peoples of California, South Africa, the Karabakh region, and pre-industrial Scandinavia have used this material to make baskets and candle wicks. There are also potential medical uses for Juncus, with both traditional medicinal uses from China and indigenous Americans as well as findings in modern medical science.

Classification

In Juncus effusus (and other species in J. sect. Juncotypus), the bract appears as a continuation of the stem, and the inflorescence appears lateral.

The genus Juncus was first named by Carl Linnaeus in his 1753 Species Plantarum. The type species of the genus was designated by Frederick Vernon Coville, who in 1913 chose the first species in Linnaeus' account, Juncus acutus. Juncus can be divided into two major groups, one group with cymose inflorescences that include bracteoles, and one with racemose inflorescences with no bracteoles.

In 2013 the genus Oreojuncus was separated from Juncus. In 2022 Viktorie Brožová et al. published a phylogenetic analysis of the cyperids (families Juncaceae, Cyperaceae, and Thurniaceae) which found Juncus to be paraphyletic, and the authors proposed that six new genera, Alpinojuncus, Agathryon, Australojuncus, Boreojuncus, Juncinella, and Verojuncus, be split from Juncus. As of July 2025 Plants of the World Online accepts Juncinella but treats the others as synonyms of Juncus.

The genus is divided into the following subgenera and sections:

Species

Selected Juncus species
J. inflexus
J. jacquinii
J. squarrosus
J. trifidus

As of July 2025, Plants of the World Online accepts 342 species:

Formerly placed here

References

  1. 1 2 3 4 "Juncus L." Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 21 July 2025.
  2. 1 2 Ralph E. Brooks; Steven E. Clemants (2000). "Juncus". Magnoliophyta: Alismatidae, Arecidae, Commelinidae (in part), and Zingiberidae. Flora of North America. Vol. 22. Oxford University Press. ISBN 0-19-513729-9.
  3. 1 2 Kirschner, Jan, ed. (2002), Species plantarum. 7: Juncaceae 2: Juncus subg. Juncus / comp. by Jan Kirschner, Canberra: Australian Biological Resources Study, ISBN 978-0-642-56823-6
  4. 1 2 3 4 D. M. D. Yakandawala; U. M. Sirisena; M. D. Dassanayake (2005). "Two new records of Juncus species (rush family – Juncaceae) in Sri Lanka" (PDF). Ceylon Journal of Science. 33: 67–76.[permanent dead link]
  5. ↑ James Ebenezer Bicheno (1819). "XVII. Observations on the Linnean genus Juncus, with the characters of those species, which have been found growing wild in Great Britain". Transactions of the Linnean Society of London. 12 (2): 291–337. doi:10.1111/j.1095-8339.1817.tb00229.x.
  6. ↑ Peter W. Ball; A. A. Reznicek; David F. Murray (27 February 2003). "210. Cyperaceae Jussieu". In Flora of North America Committee (ed.). Magnoliophyta: Commelinidae (in part): Cyperaceae. Flora of North America. Vol. 23. Oxford University Press. ISBN 978-0-19-515207-4.
  7. 1 2 3 4 Jan Kirschner; Lázaro J. Novara; Vladimir S. Novikov; Sven Snogerup; Zdeněk Kaplan (1999). "Supraspecific division of the genus Juncus (Juncaceae)". Folia Geobotanica. 34 (3): 377–390. Bibcode:1999FolGe..34..377K. doi:10.1007/BF02912822. JSTOR 4201385. S2CID 31779452.
  8. ↑ K. L. Wilson; L. A. S. Johnson (2001). "The genus Juncus (Juncaceae) in Malesia and allied septate-leaved species in adjoining regions". Telopea. 9 (2): 357–397. Bibcode:2001Telop...9..357W. doi:10.7751/telopea20013009.
  9. ↑ Huang, Shuang-Quan; Xiong, Ying-Ze; Barrett, Spencer C. H. (November 2013). "Experimental Evidence of Insect Pollination in Juncaceae, a Primarily Wind-Pollinated Family". International Journal of Plant Sciences. 174 (9): 1219–1228. Bibcode:2013IJPlS.174.1219H. doi:10.1086/673247. ISSN 1058-5893.
  10. 1 2 "Juncus L. (genus) – species list & taxonomy | PlantaeDB". plantaedb.com. Retrieved 9 February 2026.
  11. 1 2 Syranidou, Evdokia; Christofilopoulos, Stavros; Kalogerakis, Nicolas (25 September 2017). "Juncus spp.—The helophyte for all (phyto)remediation purposes?". New Biotechnology. EBC-VI: Recent Advances in Environmental Biotechnology. 38 (Pt B): 43–55. Bibcode:2017NBiot..38...43S. doi:10.1016/j.nbt.2016.12.005. ISSN 1871-6784. PMID 28040555.
  12. ↑ Greksa, Amela; Mihajlović, Ivana; Ljubojević, Mirjana; Blagojević, Boško; Vijuk, Mirjana I.; Podunavac-Kuzmanović, Sanja; Kovačević, Strahinja; Štrbac, Mirna P. (28 July 2024). "Investigation of Juncus and Iris Plant Potential—Two Native Serbian Species for Utilization in Nature-Based Solutions towards Improving the Quality of Water Contaminated with Zinc and Supporting Biodiversity". Sustainability. 16 (15): 6467. Bibcode:2024Sust...16.6467G. doi:10.3390/su16156467. ISSN 2071-1050.
  13. ↑ Cronk, J.K.; Fennessy, M.S. (1 January 2009). "Wetland Plants". Earth Systems and Environmental Sciences: 590–598. doi:10.1016/B978-012370626-3.00060-0. ISBN 978-0-12-370626-3.{{cite journal}}: CS1 maint: periodical has ISBN (link)
  14. ↑ Boughton, Elizabeth H.; Quintana-Ascencio, Pedro F.; Bohlen, Patrick J. (5 September 2010). "Refuge effects of Juncus effusus in grazed, subtropical wetland plant communities". Plant Ecology. 212 (3): 451–460. doi:10.1007/s11258-010-9836-4. ISSN 1385-0237.
  15. ↑ "Juncus roemerianus". www.fs.usda.gov. Retrieved 10 February 2026.
  16. ↑ Hoag, Chris J. "Reference Guide for the Collection and Use of Ten Common Wetland Plants of the Great Basin and Intermountain West" (PDF).
  17. ↑ Yoon, Ji-Hyun; Kim, Heung-Tae; Nam, Jong-Min; Kim, Jae-Geun (1 June 2011). "Optimal environmental range for Juncus effusus, an important plant species in an endangered insect species (Nannopya pygmaea) habitat in Korea". Journal of Ecology and Environment. 34 (2): 223–235. Bibcode:2011JEcEn..34..223Y. doi:10.5141/JEFB.2011.024. ISSN 2287-8327.
  18. ↑ Blossfeld, Stephan; Schreiber, Christina Maria; Liebsch, Gregor; Kuhn, Arnd Jürgen; Hinsinger, Philippe (26 March 2013). "Quantitative imaging of rhizosphere pH and CO2 dynamics with planar optodes". Annals of Botany. 112 (2): 267–276. doi:10.1093/aob/mct047. ISSN 1095-8290. PMC 3698388. PMID 23532048.
  19. ↑ Watson, E. B.; Wigand, C.; Cencer, M.; Blount, K. (1 February 2015). "Inundation and precipitation effects on growth and flowering of the high marsh species Juncus gerardii". Aquatic Botany. 121: 52–56. Bibcode:2015AqBot.121...52W. doi:10.1016/j.aquabot.2014.10.012. ISSN 0304-3770. OSTI 2279862.
  20. ↑ Touchette, B. W. (19 September 2006). "Salt tolerance in a Juncus roemerianus brackish marsh: Spatial variations in plant water relations". Journal of Experimental Marine Biology and Ecology. 337 (1): 1–12. doi:10.1016/j.jembe.2006.05.011. ISSN 0022-0981.
  21. ↑ Ervin, Gary N.; Wetzel, Robert G. (February 2002). "Influence of a dominant macrophyte, Juncus effusus, on wetland plant species richness, diversity, and community composition". Oecologia. 130 (4): 626–636. Bibcode:2002Oecol.130..626E. doi:10.1007/s00442-001-0844-x. ISSN 0029-8549. PMID 28547266.
  22. ↑ Rietl, Anthony J.; Overlander, Megan E.; Nyman, Andrew J.; Jackson, Colin R. (February 2016). "Microbial Community Composition and Extracellular Enzyme Activities Associated with Juncus roemerianus and Spartina alterniflora Vegetated Sediments in Louisiana Saltmarshes". Microbial Ecology. 71 (2): 290–303. Bibcode:2016MicEc..71..290R. doi:10.1007/s00248-015-0651-2. ISSN 0095-3628. PMID 26271740.
  23. ↑ Angiosperm Fruits and Seeds from the Middle Miocene of Jutland (Denmark) by Else Marie Friis, The Royal Danish Academy of Sciences and Letters 24:3, 1985
  24. 1 2 Merrill, Ruth Earl. PLANTS USED IN BASKETRY BY THE CALIFORNIA INDIANS. University of California Publications in Am. Arch. and Ethn.
  25. 1 2 Traynor, C. H.; Kotze, D. C.; McKean, S. G. (22 July 2010). "Wetland craft plants in KwaZulu-Natal: an ecological review of harvesting impacts and implications for sustainable utilization". Bothalia. 40 (1): 135–144. Bibcode:2010Botha..40..135T. doi:10.4102/abc.v40i1.202. ISSN 2311-9284.
  26. ↑ Svanberg, Ingvar (1997). "The Use of Rush (Juncus) and Cotton-Grass (Eriophorum) as Wicks: An Ethnobotanical Background to a Faroese Riddle". Svenska Landsmål och Svenskt Folkliv (323): 145–157.
  27. ↑ "Study on the species Juncaceae and Poaceae distributed in lowland areas of Karabakh and their ethnobotanical characteristics" (PDF). Plant & Fungal Research. 2025. doi:10.30546/2664-5297.2025.8.1.021. ISSN 2664-5297.
  28. ↑ Setzer, William N. (12 November 2018). "The Phytochemistry of Cherokee Aromatic Medicinal Plants". Medicines. 5 (4): 121. doi:10.3390/medicines5040121. ISSN 2305-6320. PMC 6313439. PMID 30424560.
  29. ↑ Ullah, Sana; Amen, Yhiya; Shimizu, Kuniyoshi (16 September 2024). "Phytochemical, ethnomedicinal uses and pharmacological profile of Juncus decipiens (Buchenau) Nakai (common rush)". Natural Product Research. 38 (18): 3253–3263. doi:10.1080/14786419.2023.2223749. ISSN 1478-6419.
  30. ↑ Barta, Anita; Salusso, Agostina; Kúsz, Norbert; Berkecz, Róbert; Schlauer, Jan; Purger, Dragica; Hohmann, Judit; Carpinella, Maria Cecilia; Vasas, Andrea (9 August 2024). "Phenanthrenes from Juncus articulatus with Antibacterial and Biofilm Formation Inhibitory Activity". Journal of Natural Products. 87 (8): 2068–2080. Bibcode:2024JNAtP..87.2068B. doi:10.1021/acs.jnatprod.4c00577. ISSN 0163-3864. PMID 39121346.
  31. ↑ Brožová, Viktorie; Proćków, Jarosław; Záveská Drábková, Lenka (2022). "Toward finally unraveling the phylogenetic relationships of Juncaceae with respect to another cyperid family, Cyperaceae". Molecular Phylogenetics and Evolution. 177 107588. Bibcode:2022MolPE.17707588B. doi:10.1016/j.ympev.2022.107588. ISSN 1055-7903. PMID 35907594.