Juncus effusus L.

Last updated: 29 June 2015

Scientific Name

Juncus effusus L.


Juncus bogotensis Kunth, Juncus communis E.Mey. [Illegitimate], Juncus fistulosus Guss., Juncus laevis Wallr. [Illegitimate], Juncus lucens Burnham, Juncus luxurians Colenso, Juncus mauritianus Bojer [Invalid], Juncus zebrinus André. [1]

Vernacular Name

English Soft rush, common rush, mat rush, Japanese mat rush, mating rush, tatami reed [2][3]
China Deng xin cao, hu hsu tao, teng hsin tsao [3]
Indonesia Sumpu, udulan (Javanese) [2]
Philippines Sud­sud (lgorot); pingot, balili (Bontoc) [2]
Vietnam C[aa]y b[aas]c, b[aas]c d[ef]n, d[aw]ng t[aa]m th[ar]o [2]
France Jonc à lier, jonc épars [2]

Geographical Distributions

Juncus effusus is widely distributed in the temperate zones of the world, especially in the northern hemi­sphere, and the mountainous parts of the tropics, but it is not found in Australia. It is native to Southeast Asia where it is found in Malaysia (Sabah, Sarawak), Indonesia (Aceh, Java, Kali­mantan), the Philippines (from Luzon to Min­danao), New Guinea, northern Thailand and Viet­nam. J. effusus is cultivated in Japan, China, Tai­wan, the Philippines and northern Vietnam. It is sometimes considered a weed, for instance in pas­tures. [2]

Botanical Description

J. effusus is comes from the family Junaceae. It is a semi-aquatic, sedge-like, dense­ly tufted, erect, hairless, rhizomatous and perennial herb that can grow 40-120 cm tall. Its rhizome is tough, creeping­ horizontal, short, very short-jointed and scaly. The stem is cylindrical with continuous pith, measures 1-3 mm thick, and not or hardly ribbed (when dried, very closely-set faint longitudinal ribs are visible). [2]

The leaves are represented by basal scale-like sheaths. There are several sheaths which embrace the stem, red-brown, bladeless, obtuse, measure 5-12 cm long and often with a deciduous awn at the apex. [2]

The inflores­cence is a pseudolateral, dense or lax cymose panicle and usually many-flowered and measures 1-10(-15) cm long. The bract of the inflorescence is erect, cylindrical, acute at apex, simulates a continuation of the stem and overtops the inflorescence by 14-25 cm. The flowers are partly sessile. They are partly stalked with petiole 8 mm long. The 2 thin floral bracts are very close together, ovate and measure about 0.7-0.8 mm long. There are 6 perianth segments which are subequal, narrowly ovate-Iance-shaped, measure 2-3.5 mm long, firm with transparent thin margins, with very acute apex and yellowish to pale green. There are 3(-6) stamens which are much shorter than the tepals, with anthers scarcely 1 mm long and are equal or shorter than the filaments. The pistil is with a sessile ovary and very short style. The 3 slender stigmas are long and erect. [2]

The fruit is a 3-valved capsule, three-angled-oblong, measures 2-3 mm long, brown and with nu­merous seeds. The seed is broadly ellipsoid, measures about 0.4-0.5 mm long, apiculate and finely reticulate. [2]


No documentation

Chemical Constituent

No documentation

Plant Part Used

No documentation

Traditional Use

No documentation

Preclinical Data

No documentation

Clinical Data

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No documentation

Poisonous Management

No documentation

Line drawing



Figure 1: The line drawing of J. effuses. [2]


  1. The Plant List. Ver1.1. Juncus effusus L. [homepage on the Internet]. c2013 [updated 2012 Mar 23; cited 2015 June 29]. Available from: http://www.theplantlist.org/tpl1.1/record/kew-314902
  2. Juncus effusus L. In: Brink M, Escobin RP, editors. Plant Resources of South-East Asia No. 17: Fibre Plants. Leiden, Netherlands: Backhuys Publishers; 2003.
  3. Quattrocchi U. CRC World Dictionary of Plant Names: Common names, scientific names, eponyms, synonyms, and etymology. Volume III E-L. Boca Raton, Florida: CRC Press; 2012. p. 637-638.