categoryZGrasses Grasses List 

JOINTED RUSH

Juncus articulatus

Rushes Family [Juncaceae]

month8jul month8july month8aug

category
category8Grasses
 
status
statusZnative
 
flower
flower8brown
 
inner
inner8cream
 
morph
morph8actino
 
petals
petalsZ6
(3+3)
stem
stem8round
 

2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD
At up to 0.8m tall (but usually much shorter) it is shorter than the similar up to 1.1m tall Sharp-Flowered Rush.


2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD
Grows in dampish grassland usually on acidic soils.


4th July 2015, Leasowe Lighthouse, Moreton, Wirral. Photo: © RWD
In the flowering stage. It is distinguished from the very similar Salt-marsh Rush (Juncus gerardii) by the styles which are twice as long as the stamens (similar sizes for J. gerardii)


4th July 2015, Leasowe Lighthouse, Moreton, Wirral. Photo: © RWD
Style in the centre, which will enlarge to become the dark-brown fruit.


4th July 2015, Leasowe Lighthouse, Moreton, Wirral. Photo: © RWD
The style has a spiralled three-pronged hairy stigma, the hairs being transparent and looking like miniature frozen icicles. The stamens are flattened spiralling strips with two short prongs atop.


2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD
It is multiply branched, with brown (here nearly black) tepals and fruits. Bract reaches up to the flowers, but not above.


2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD
Each flower has six pointed tepals (rather than petals) surrounding a central brown fruit.


2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD


2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD
The six tepals (three inner, three outer) are blackening brown and taper to a point (centre, far right) and surround the growing fruits which are also blackening from brown and taper abruptly to concave point.


2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD
The fruits are tipped with the remains of withered stamens which once split into three at the end like a propeller (not shown).


2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD
Close-up of spikelets.


2nd Aug 2009, Pendleton, Greater M/cr. Photo: © RWD
Close-up of spikelets, stamens on ends of fruits withered.


Hybridizes with :

  • Sharp-Flowered Rush (Juncus acutiflorus) to form (Juncus × surrejanus)
  • Alpine Rush (Juncus alpinoarticulatus) to form (Juncus × alpiniformis)

Easily confused with : Salt-marsh Rush (Juncus gerardii) but that has styles about as long as the stamens (in Jointed Rush the styles are twice as long as the stamens)

Many similarities to : Sharp-Flowered Rush (Juncus acutiflorus), with which it also hybridizes.

Some similarities to : Blunt-flowered Rush (Juncus subnodulosus)

No relation to : Flowering-Rush [a plant with similar name belonging to a totally different family].


  Juncus articulatus  ⇐ Global Aspect ⇒ Juncaceae  

Distribution
 family8Rushes family8Juncaceae
 BSBI maps
genus8Juncus
Juncus
(Rushes)

JOINTED RUSH

Juncus articulatus

Rushes Family [Juncaceae]