categoryZGrasses Grasses List 

COMMON SEDGE

BLACK SEDGE

Carex nigra

Sedge Club- & Spike-Rush Family [Cyperaceae]

month8apr month8april month8may

category
category8Grasses
 
 
status
statusZnative
 
 
flower
flower8brown
 
 
flower
flower8cream
 
 
inner
inner8brown
 
 
petals
petalsZ0
 
 
type
typeZspiked
 
 
stem
stem8triangular
 
 
stem
stem8hollow
triangular
hole
sex
sexZmonoecious
 
 

21st May 2005, Grammars Common, IoW. Photo: (CC by 2.0) Geoff Toone
It forms small tussocks; these are very small tussocks. They have underground rhizomes which may be very short.


21st May 2005, Grammars Common, IoW. Photo: (CC by 2.0) Geoff Toone
The stems grow to 70cm long and feel smooth. re is a male flower spikelet at the top of this one in the top right corner.


21st May 2005, Grammars Common, IoW. Photo: (CC by 2.0) Geoff Toone
The leaves are glaucous green.


29th May 2012, inclined plane, Whinberry Naze, Rawtenstall Photo: © RWD
Unfortunately this stem has all but the bottom-most female spike of pale-green fruits with a smaller pair of glumes around them; other female spike and thee topmost male spike are totally missing from this specimen - a fact that your Author failed to notice when photographing this specimen! The stems have rounded angles. It lacks a sheath.


29th May 2012, inclined plane, Whinberry Naze, Rawtenstall Photo: © RWD
The stems are ribbed. The lowest bract is shorter than or equal to the length of the inflorescence.

The female florets are quite distinctive having large pale green fruits which are 2.5 to 3.5mm long - larger than the smaller, almost black, glumes (themselves with a pale-green stripe running up the centre almost to the tip) which cup the developing fruit within. The glumes are mostly blunt at the tip except for the lowest ones. They also have just a narrow paler periphery.



29th May 2012, inclined plane, Whinberry Naze, Rawtenstall Photo: © RWD
The beak at the tip of the pale-green flattened-oval fruit is less than or equal to 2mm long.

There are two long, white, fuzzy styles emerging from each pale-green fruit.


Hybridizes with :

  • Tufted Sedge (Carex elata) to produce Carex × turfosa which is only partially fertile and occurs with a scattered distribution in England, Wales and Ireland.
  • Stiff Sedge (Carex bigelowii) to produce Carex × decolorans which is again only partially fertile and many of them resemble one parent more than the other which means that they probably back-cross.

It is native occupying a wide range of habitats from wet acidic to basic soils and all intermediates. In keeping with its common name it is common throughout the British Isles - and is probably the commonest of sedges but also the most variable in characteristics.


  Carex nigra  ⇐ Global Aspect ⇒ Cyperaceae  

Distribution
 family8Sedge Club- & Spike-Rush family8Cyperaceae
 BSBI maps
genus8Carex
Carex
(Sedge)

COMMON SEDGE

BLACK SEDGE

Carex nigra

Sedge Club- & Spike-Rush Family [Cyperaceae]