categoryZGrasses Grasses List 

GLAUCOUS SEDGE

Carex flacca

Sedge Club- & Spike-Rush Family [Cyperaceae]

Flower:
month8apr month8april month8may
Fruit:
fruit8jun fruit8june fruit8jul fruit8july fruit8aug fruit8sep fruit8sept

category
category8Grasses
 
status
statusZnative
 
flower
flower8brown
male
flower
flower8green
female
petals
petalsZ0
 
type
typeZspiked
 
stem
stem8triangular
 
stem
stem8hollow
pin-hole
sex
sexZmonoecious
 

July 2014, greywell Fenn, Hampshire Photo: © Simon Melville
At the fruiting stage later in the season. The male flowers ar at the top and turned brown. The female flowers are below and turned into fruit, which are green for the moment. Note that one of the spikes of flowers above the centre has not decided whether it is all male or all female and is a mixture. They can do this on Glaucous Sedge.

Note that the stems are glaucous, and can be either glaucous green or glaucous green-blue as this specimen.



31st May 2016, Gait Barrows, Lancs. Photo: © RWD
  Turning to fruit after flowering, thin male flowers at top (anthers withered to white) and female flowers below (styles withered to fawn-colour and fruits beginning to form (pale green at first).


10th May 2015, Nob End SSSI, Bolton, Lancs. Photo: © RWD
  A young and short specimen. Several (2 to 3) male flowers spikes at summit, fewer female flower spikes underneath them. Stems and leaves glaucous green.


10th May 2015, Nob End SSSI, Bolton, Lancs. Photo: © RWD
 Female flower. The three styles of Glaucous Sedge are the fuzzy pale cream things protruding from the dark-brown glumes. (The similar Black Sedge has but two styles).


10th May 2015, Nob End SSSI, Bolton, Lancs. Photo: © RWD
 Long cream-coloured stamens on male flower spike; the darker ones are spent.


9th June 2018, Keen of Hamar, Shetland. Photo: © Jill Stevens
   There seems to be only one male flower-spike on this specimen, and likewise only one female flower-spike. The anthers of the male florets have turned a shade of orange whilst the 3-styles each of the female florets below have mostly turned brown. See Keen of Hamar or Serpentinic Rocks for some reasons why plants groing on the Keen of Hamer often differ in form to the same species growing on mainland Britain.


13th May 2011, High Park Wood, under Whitbarrow, Cumbria. Photo: © RWD
  A short to medium sedge to 60cm. Similar to Black Sedge (Carex nigra) but that has flowers with only two styles; this has three styles. With 2-3 male catkins (at the top) and perhaps three thicker pale-green female catkins below them, the lowest drooping downwards. This is a young specimen where the lowest spike has not yet become pendant.


13th May 2011, High Park Wood, under Whitbarrow, Cumbria. Photo: © RWD
 Male spikes thin, dark-brown, with white stamens protruding.


13th May 2011, High Park Wood, under Whitbarrow, Cumbria. Photo: © RWD
  There are three fluffy white styles (which turn brown and shrivel) coming from the top of each pale-green ovary. The grassy leaves are finely ridged. In cross-section the stem (right-most) is triangular with rounded corners and with a small-diameter and round hollow tube up the centre (in other species of sedge, this hollowness can be larger, triangular or absent altogether).


13th May 2011, High Park Wood, under Whitbarrow, Cumbria. Photo: © RWD
 The shape of the lime-green ovaries (which will become the fruit when pollinated) is very distinctive in Glaucous Sedge - they are oval in cross section and egg-shaped from the flatter side and almost lacking a beak (which is present in various shapes and lengths on most other sedges). However, this specimen is immature, and the thin utricle surrounding each pale-green ovary has not yet filled-out properly, and when they do, the ovaries will be more spherical in diametric cross-section.


13th May 2011, High Park Wood, under Whitbarrow, Cumbria. Photo: © RWD
 Female catkins are pale-green with two well-separated dark-brown bracts (actually called glumes) on the visible pale-green ovary.


3rd June 2017, Reynards Lane, Hartington, White Peaks. Photo: © RWD
 Male catkin at top,   Female catkin bottom.


3rd June 2017, Reynards Lane, Hartington, White Peaks. Photo: © RWD
 Female catkin. The three hairy styles each fruit possesses have writhed about.


3rd June 2017, Reynards Lane, Hartington, White Peaks. Photo: © RWD
 Female catkin. Hairy styles. Green fruits with glumes which have brown edges.


3rd June 2017, Reynards Lane, Hartington, White Peaks. Photo: © RWD
 Female catkin. With junction to the triangular stem, which has a striated leaf and bract.


13th May 2011, High Park Wood, under Whitbarrow, Cumbria. Photo: © RWD
The leaves are glaucous and grass-like, but fairly short.


13th May 2011, High Park Wood, under Whitbarrow, Cumbria. Photo: © RWD
Many leaves sheathe-off very close to the ground.


8th May 2008, unknown place Photo: (CC by 2.0) Geoff Toone
Herbarium specimens follow. The whole plant (minus roots) of one, folded at the top to fit on the paper.


8th May 2008, unknown place Photo: (CC by 2.0) Geoff Toone
The leaves, which have a shallow V-groove down the centre.


8th May 2008, unknown place Photo: (CC by 2.0) Geoff Toone
Two male narrower spikes with white anthers at the top; two wider female spikes with developing green and brown fruit at the bottom.


8th May 2008, unknown place Photo: (CC by 2.0) Geoff Toone
The fruits up close. Take note of the widths and shapes of the green and the brown areas. This helps ID Glaucous Sedge.


8th May 2008, unknown place Photo: (CC by 2.0) Geoff Toone
The male florets with anthers and long white filaments up close. Take note of the widths and shapes of the white and the brown areas. This helps ID Glaucous Sedge.


Easily mistaken for : Black Sedge (Carex nigra) - see photo captions.

No relation to : Sedges which are not in the Carex genus such as Flat Sedge (Blysmus compressus), False Sedge (Kobresia simpliciuscula) and White Beak-sedge (Rhynchospora alba) although all are in the same family, Cyperaceae.

One of the commonest sedges (and a true sedge) found on alkaline grassland, dunes, fens, meadows, flushes, and mountain grasslands. It fruits June to September. This is one of those Sedges with no known hybrids, of which there are about 49. Fewer Sedges hybridize (about 37); but some with many different bedfellows yielding a plethora of hybrids (about 42). All true sedges have separate male and female catkins, but both on the same plant. That is, un-like grasses, the flowers themselves are not bisexual.


  Carex flacca  ⇐ Global Aspect ⇒ Cyperaceae  

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

GLAUCOUS SEDGE

Carex flacca

Sedge Club- & Spike-Rush Family [Cyperaceae]